I have heard a lot of people (where I am from, India) say that one must drink water sitting, not standing. Recently, I also came across a video that said the same thing (link). The reason given is that when you drink water standing, it goes to the colon too quickly, whereas while sitting, the water is better absorbed by the organs. Is this true? Is there a biological basis for why I should drink water sitting?
I tried to find literature on this matter, but apparently there isn't a whole lot. I found this paper where they tried to see the water passage rate in the GI tract of rabbits, mentioning how the water goes from stomach to cecum to proximal large colon, but obviously did not study posture.
Note: I think this question belongs here better than Skeptics.SE as I am looking for a biological explanation
The stomach is equipped with the pyloric valve to regulate transpyloric flow to the duodenum.
Both cold and warm drinks stimulate a pattern of motility associated with retardation of transpyloric flow.
The pyloric valve is responsible for acidifying water that you drink, and if the body's guard against amoeba's and dysentery depended on body position, it would be low survival performance, given that sedentary posture is associated with poorer health outcomes, including an increased risk of type 2 diabetes. You will benefit from minimizing time spent sitting each day, and from breaking up periods of time spent being sedentary, as often as possible. It's aperture at rest is 3mm, so it's of minimal difficulty for the stomach to hold water as required for optimal health. It's highly likely that water is kept for enough time to expose it to stomach acids, regardless of body position, and then it's transmitted. Water doesn't flow straight through the stomach like a straight tube when it's empty.
First off: pure, reverse osmosis treated, bottled water HAS NO NUTRIENTS. Secondly, of everything you swallow, nothing goes too fast on it's way to the colon. The small intestine is a network of twisted tubing, around 20 feet long. Nothing is going through there "Too fast".
An Explanation of Water and Your Body
Recently, I realized that I’ve been feeling pretty dehydrated no matter how much I drank, and was feeling an overall lack of energy and clear thinking. Part of this is due to it being winter. Another part is being active most nights of the week in one sport or another and sweating out my body’s water. But then part of me started thinking that why, no matter how much water I drink, am I always thirsty?
So I started researching everything about water and the body. From most of my questions, I found some answers, and other questions provided some pretty basic answers that didn’t get me anywhere.
I’ve set this up below in the form of questions with the answers I found. Hopefully at least one of these will answer something you’ve been wondering, or at least make you smarter. Feel free to astonish your friends with knowing more than them on this subject.
Water and Sodium Balance
Water and sodium are tightly connected and regulated by complex mechanisms. The volume of water you have in your body and its concentration of sodium (and other electrolytes) doesn't change much, even with significant changes in dietary intake of sodium and/or water, according to the Merck Manual. That's because, if this balance is ever thrown off, these mechanisms either excrete excess water and sodium, or trigger your thirst to make you drink more water.
The amount (or concentration) of sodium per volume of body fluid is called osmolarity. In order for you to stay healthy, osmolarity must remain within a certain range. That means, if you lose a lot of water from sweating, for example, and the concentration of water in your body gets low, your body starts to excrete sodium in your urine with the help of your kidneys. Getting rid of the extra sodium helps maintain the osmolarity, since the volume of water has gone down.
On the other hand, if you drink a lot of water and the volume of your body fluid goes up, the body will actually hold onto the sodium in an effort to maintain that osmolarity so that the fluid doesn't get too diluted. Similarly, if you consume too much sodium, the body will hold onto water to maintain that same concentration. This is why consuming a lot of sodium is connected to high blood pressure.
Since the body holds onto water and sodium with increasing consumption of either, the volume of fluid in the blood vessels goes up (even though the diameter of the blood vessels doesn't change) and the heart has to work harder to pump it. In other words, your body is trying to push a larger amount of fluid through the same-size tunnel. This puts extra pressure on both the heart and the blood vessels.
For about 25 percent of the population, who are described as "salt-sensitive," this happens immediately after eating a high-salt meal and is only temporary, according to a September 2015 report in Nutrition Reviews. For others, this leads to chronically high blood pressure. Luckily, there are natural ways to lower blood pressure that are pretty simple to incorporate.
Knowledge Subject 1: Biology
Topic 1: Cell Biology
You need to know certain cell organelles (parts of cells), their functions, and whether they are found in animal or plant cells.
Animal Cell Structure
Lysosomes hold enzymes. Lysosomes digest food or break down the cell when it dies.
Mitochondria are organelles that act like a digestive system, which takes in nutrients, breaks them down, and creates energy-rich molecules (ATP) for the cell.
The cell nucleus acts as the brain of the cell. It contains the cell's DNA, or the genetic information, from which proteins are made (see Topic 2, coming up next). It also helps control eating, movement, and reproduction.
Chloroplasts only exist in plant cells and assist in the process of photosynthesis, converting light into energy (which only plants do, not animals).
The cell membrane holds all of the pieces of the cell and serves as the barrier between the cell and other cells.
Below is a sample question where you need an understanding of these organelles to select the correct answer. The chemical reaction mentioned in the passage was photosynthesis.
Knowing that photosynthesis happens in chloroplasts, I can correctly choose answer F.
But nowhere in the passage was it said that chloroplasts are where photosynthesis happens! This is a fact you had to know before the test.
While there are many other organelles, the ones listed above and ribosomes (which I will cover in the next topic) should be the only organelles you need to know for the test. Also, you should not need to know any other information about these organelles. If you would like to do more reading on these topics, click here.
Topic 2: DNA, RNA, Ribosomes, and Protein Synthesis
DNA contains the genetic information needed for making proteins (protein synthesis). Protein synthesis involves DNA, RNA, ribosomes, and proteins. DNA acts as the blueprint for protein production.
The Process of Protein Synthesis
Messenger RNA (known as mRNA) makes a copy of the sequence of DNA of a specific gene. This process is known as transcription and happens in the nucleus.
Once the mRNA is made, it leaves the nucleus and enters the cytosol of the cell. Ribosomes use mRNA as a guide to make protein of the same amino acid sequence as the original DNA. The process of producing protein from the mRNA is referred to as translation. So, the process of protein synthesis consists of two steps: DNA to mRNA transcription and mRNA to protein translation. If you would like to read a more detailed summary, click here.
Topic 3: Natural Selection
Natural selection is also known as 'survival of the fittest.' In a specific environment, traits that allow organisms to reproduce more effectively will become more common, and traits that reduce reproductive success will become less common. A classic example of this is the change in peppered moth color during the industrial revolution.
In England, the burning of coal during the industrial changed tree bark from light brown to dark brown in color. The peppered moth blended in perfectly and was hidden from predators. However, once clean air acts were passed, the trees quickly returned to a lighter color, making the dark moths easily visible to predators. Meanwhile, lighter colored moths were still hidden from view and survived to lay eggs. Thus, because of natural selection, over the course of years, the moths turned from dark to light in color! Click here for more information.
The Strong Survive, the Weak Hang On
Topic 4: Greenhouse Gases
Greenhouse gases are gases that trap heat in the atmosphere. Sunlight can pass through them as it goes towards the earth, but greenhouse gases prevent the heat sunlight produces at Earth's surface from leaving the atmosphere. This mean the heat stays close to Earth, increasing the planet's temperature. Human activity has caused the amount of greenhouse gases in the atmosphere to increase in recent decades, and they are a major contributor to climate change.
There are six main greenhouse gases:
- Carbon dioxide (CO2)
- Methane (CH4)
- Nitrous oxide (N2O)
- Ozone (O3)
- Water Vapor (H2O)
- Fluorinated gases (also known as chlorofluorocarbons or CFCs)
Look at this sample question:
The correct answer is is J because methane (CH4), as a greenhouse gas, absorbs heat not when it enters the earth from space, but when it comes up from the earth. This causes warming.
Topic 5: Photosynthesis and Respiration
Photosynthesis is the process where plants capture sunlight to make food for themselves. During photosynthesis, the plant takes in carbon dioxide, water, and energy, and it produces glucose (which it consumes to live) and oxygen (which humans and other animals breathe). You don't need to memorize the formula for photosynthesis, but you may see it on the ACT, and it's useful to understand it ahead of time. This is what it looks like:
Respiration is basically the inverse of photosynthesis. Respiration is when cells break down molecules into a type of energy they can use. While only plants go through photosynthesis, both plants and animals go through respiration. In respiration, glucose and oxygen are converted into carbon dioxide, water, and ATP (a chemical that provides energy to cells). Here's the formula:
Topic 6: Taxonomic Rank
Taxonomy is the science of naming and classifying all organisms. It allows scientists to see how closely different organisms are related and what characteristics they share. Taxonomic rank is the seven levels organisms are classified in. Know the seven taxonomic levels which are (from broadest to most specific):
If two species share one level of taxonomic rank, they also share all of the broader taxonomic ranks above it. So, if two species are in the same family, they are also in the same order, class, phylum, and kingdom.
Topic 7: Genetics
The genetics information you need to know for the ACT centers around which traits are passed on to offspring. The key genetic term to know is "allele". Alleles are pairs of genes responsible for particular traits. Allele pairs can be made up of two dominant genes, two recessive genes, or a dominant and recessive gene. Dominant genes are usually expressed as capital letters and recessive genes are expressed as lower-case letters. So an allele pair shown as "Tt" would have one dominant and one recessive allele.
ABNORMAL EATING AND SWALLOWING
Dysphagia (abnormal swallowing) can result from a wide variety of diseases and disorders ( Table 2 ). 40 , 41 Functional or structural deficits of the oral cavity, pharynx, larynx, esophagus, or esophageal sphincters can cause dysphagia. Dysphagia may lead to serious complications including dehydration, malnutrition, pneumonia, or airway obstruction. In dysphagia rehabilitation, we consider how a given abnormality affects both bolus passage and airway protection.
Diseases and disorders causing dysphagia
Table 28.2 Selected causes of oral and pharyngeal dysphagia
|Neurologic disorder and stroke||Structural Lesions||Psychiatric Disorder|
|Cerebral infarction||Thyromegaly||Psychogenic dysphagia|
|Brain-stem infarction||Cervical hypertosis|
|Intracranial hemorrhage||Congenital web||Connective tissue diseases|
|Parkinson's disease||Zenker's diverticulum||Polymyositis|
|Multiple sclerosis||Ingestion of caustic material||Muscular Dystrophy|
|Motor neuron disease||Neoplasm|
|Myasthenia gravis||Surgical resection|
Palmer JB, Monahan DM, Matsuo K: Rehabilitation of Patients with Swallowing Disorders. In: Braddom R (Ed): Physical Medicine and Rehabilitation. Philadelphia: Elsevier, 2006, pp. 597-616.
Structural abnormalities can be congenital or acquired. Cleft lip and palate is one congenital structural abnormality. It hampers labial control for sucking, decreases the oral suction, and causes insufficiency of velopharyngeal closure with nasal regurgitation. Mastication can be impaired by the undergrowth of the maxilla and malalignment of the teeth.
Cervical osteophytes are bony outgrowths from the cervical vertebrae, commonly occurred in the elderly. They may narrow the food path way and direct the bolus toward the airway ( Fig. 7 ). 42 Diverticulae can occur in the pharynx or esophagus. A Zenker diverticulum is a pulsion diverticulum of the hypopharynx that occurs at a weak spot in the muscular wall. Its entrance is located just above the cricopharyngeus muscle, but the body of the pouch can extend much lower. 43 The bolus can enter in the diverticulum and be regurgitated to the pharynx, which may result in coughing or aspiration.
Partially obstructive C6-7 anterior osteophyte (arrow). It impinges on the column of barium, narrowing the lumen by more than 50%.
Webs or strictures may occur in the pharynx, esophagus, or sphincters. These can obstruct bolus passage and are usually more symptomatic with solid foods that liquids. A common site for narrowing is the UES. Failure to open the UES may be structural (due to a web or stricture) or functional (due to weakness of the muscles that open the UES). 44 It is difficult to differentiate these conditions, and empirical dilatation is recommended. Stricture is common in the body of the esophagus and is often related to gastroesophageal reflux disease. It is important to consider esophageal carcinoma in the differential diagnosis, since this disease is serious and treatment can improve both survival and quality of life.
Impairments affecting the jaw, lips, tongue, or cheek can hamper the oral phase or food processing. Reduced closing pressure of the lips may lead to drooling. Weak contraction of the tongue and soft palate can cause premature leakage of the bolus into the pharynx, especially with liquids. In weakness of the buccal or labial muscles, food can be be trapped in the buccal or labial sulci (between the lower teeth and the cheeks or gums, respectively). Tongue dysfunction produces impaired mastication and bolus formation, and bolus transport. These usually result from tongue weakness or incoordination, but sensory impairments can produce similar effects, including excessive retention of food in the oral cavity after eating and swallowing ( Fig. 8 ).
Food debris retained in the left the buccal sulcus in the mouth due to buccal muscle weakness and sensory deficits caused by a right hemisphere stroke.
Loss of teeth reduces masticatory performance. Chewing can be prolonged by missing teeth, and particle size of the triturated bolus becomes larger due to lower efficiency of mastication. 45 Xerostomia hampers food processing, bolus formation and bolus transport during eating. Chemoradiation therapy for head-and-neck cancer often causes delayed swallow initiation, decreased pharyngeal transport, and ineffective laryngeal protection. 46
Dysfunction of the pharynx can produce impaired swallow initiation, ineffective bolus propulsion, and retention of a portion of the bolus in the pharynx after swallowing. Insufficient velopharyngeal closure may result in nasal regurgitation and reduce pharyngeal pressure in swallow, hampering transport through the UES. Weakness of tongue base retraction or the pharyngeal constrictor muscles can render inadequate the force of pharyngeal propulsion, resulting in retention of all or part of the bolus in the pharynx (usually the valleculae and pyriform sinuses) after swallowing. Incomplete tilting of the epiglottus may obstruct bolus propulsion, especially with higher viscosity boluses, resulting in retention in the valleculae.
Impaired opening of the UES can cause partial or even total obstruction of the foodway with retention in the piriform sinuses and hypopharynx, increasing risk of aspiration after the swallow. Insufficient UES opening can be caused by increased stiffness of the UES, as in fibrosis or inflammation, or failure to relax the sphincter musculature, as noted above. Weakness of the anterior suprahyoid muscles can impair opening of the UES, since these muscles normally pull the sphincter open during swallowing.
Esophageal dysfunction is common and is often asymptomatic. Esophageal motor disorders include conditions of either hyperactivity (e.g., esophageal spasm), hypoactivity (e.g., weakness), or inccordination of the esophageal musculature. 47 Either of these can lead to ineffective peristalsis with retention of material in the esophagus after swallowing. Retention can result in regurgitation of material from the esophagus back into the pharynx, with risk of aspirating the regurgitated material. Esophageal motor disorders are sometimes provoked by gastroesophageal reflux disease, and in some cases, can respond to treatment with proton pump inhibitors.
Airway protection – penetration/aspiration
Airway protection is critical to swallowing, and its failure can have serious consequences. Laryngeal penetration is defined as passage of the material transported from the mouth or regurgitated from the esophagus enters into the larynx but above the vocal folds. In contrast, aspiration is defined as passage of material through the vocal folds ( Fig. 9 ). Laryngeal penetration is sometimes observed in normal individuals. Aspiration of microscopic quantities also occurs in normal individuals. However, aspiration that is visible on fluoroscopy or endoscopy is pathological, and is associated with increased risk of aspiration pneumonia or airway obstruction. 48 Aspiration can occur before, during or after swallowing. Clinicians should consider the mechanism of aspiration if it is observed on fluoroscopy or endoscopy. Impairments of airway protection can result from reduced hyolaryngeal elevation, impaired epiglottic tilt, incomplete closure of the laryngeal vestibule, or inadequate vocal fold closure due to weakness, paralysis, or anatomical fixation. These impairments can lead to aspiration, usually during the swallow. Aspiration before the swallow is commonly caused by either premature entry of liquids into the pharynx (due to impaired containment in the oral cavity) or by delayed onset of laryngeal closure after a bolus is propelled into the pharynx. Aspiration after the swallow is usually due to accumulated residue in the pharynx after the swallow. Material may be inhaled when breathing resumes after the swallow.
Videofluorographic images of laryngeal penetration (A) and aspiration (B) in dysphagic individuals swallowing liquid barium. Arrows indicate the leading edge of the barium in the airway.
The consequences of aspiration are highly variable, ranging from no discernable effect all the way to airway obstruction or severe aspiration pneumonia. The normal response to aspiration is a strong reflex coughing or throat clearing. However, laryngeal sensation is often abnormal in individuals with severe dysphagia. 49 Silent aspiration, or aspiration in the absence of visible response, has been reported in 25-30% of patients referred for dysphagia evaluations. 49 , 50 , 51 Several factors determine the effect of aspiration in a given individual, including the quantity of the aspirate, the depth of the aspiration material in the airway, the physical properties of the aspirate (acidic material is most damaging to the lung, producing chemical pneumonitis), and the individual's pulmonary clearance mechanism. 52 Poor oral hygiene can increase the bacterial load in the aspirate, increasing the risk of bacterial pneumonia.
The rectum ampulla stores fecal waste (also called stool, or poo) before it is excreted. As the waste fills the rectum and expands the rectal walls, stretch receptors in the rectal walls stimulate the desire to defecate. This urge to defecate arises from the reflex contraction of rectal muscles, relaxation of the internal anal sphincter, and an initial contraction of the skeletal muscle of the external anal sphincter. If the urge is not acted upon, the material in the rectum is often returned to the colon by reverse peristalsis, where more water is absorbed and the faeces is stored until the next mass peristaltic movement of the transverse and descending colon.
When the rectum is full, an increase in pressure within the rectum forces apart the walls of the anal canal, allowing the fecal matter to enter the canal. The rectum shortens as material is forced into the anal canal and peristaltic waves push the feces out of the rectum. The internal and external anal sphincters along with the puborectalis muscle allow the feces to be passed by muscles pulling the anus up over the exiting feces. 
Voluntary and involuntary control
The external anal sphincter is under voluntary control whereas the internal anal sphincter is involuntary. In infants, the defaecation occurs by reflex action without the voluntary control of the external anal sphincter. Defecation is voluntary in adults. Young children learn voluntary control through the process of toilet training. Once trained, loss of control, called fecal incontinence, may be caused by physical injury, nerve injury, prior surgeries (such as an episiotomy), constipation, diarrhea, loss of storage capacity in the rectum, intense fright, inflammatory bowel disease, psychological or neurological factors, childbirth, or death. 
Sometimes, due to the inability to control one's bowel movement or due to excessive fear, defecation (usually accompanied by urination) occurs involuntarily, soiling a person's undergarments. This may cause significant embarrassment to the person if this occurs in the presence of other people or a public place.
The positions and modalities of defecation are culture-dependent. Squat toilets are used by the vast majority of the world, including most of Africa, Asia, and the Middle East.  The use of sit-down toilets in the Western world is a relatively recent development, beginning in the 19th century with the advent of indoor plumbing. 
Regular bowel movements determine the functionality and the health of the alimentary tracts in human body. Defecation is the most common regular bowel movement which eliminates waste from the human body. The frequency of defecation is hard to identify, which can vary from daily to weekly depending on individual bowel habits, the impact from the environment and genetic.  If defecation is delayed for a prolonged period the fecal matter may harden, resulting in constipation. If defecation occurs too fast, before excess liquid is absorbed, diarrhea may occur.  Other associated symptoms can include abdominal bloating, abdominal pain, and abdominal distention.  Disorders of the bowel can seriously impact quality of life and daily activities. The causes of functional bowel disorder are multifactorial, and dietary habits such as food intolerance and low fiber diet are considered to be the primary factors. 
Constipation, also known as defecatory dysfunction, is the difficulty experienced when passing stools. It is one of the most notable alimentary disorders that affects different age groups in the population. The common constipation is associated with abdominal distention, pain or bloating.  Researches revealed that the chronic constipation complied with higher risk of cardiovascular events such as 'coronary heart disease and ischemic stroke', while associating with an increasing risk of mortality.  Besides the dietary factors, the psychological traumas and 'pelvic floor disorders' can also cause the chronic constipation and defecatory disorder respectively.  Multiple interventions, including physical activities, 'high-fibre diet', probiotics  and drug therapies can be widely and efficiently used to treat constipation and defecatory disorder.
Inflammatory bowel diseases
Inflammatory disease is characterized as a long-lasting chronic inflammatory throughout the gastrointestinal tract. Crohn's disease (CD) and ulcerative colitis (UC) are the two universal type of inflammatory bowel diseases that have been studied over a century, and they are closely related to different environmental risk factors, family genetic and people's lifestyle such that smoking is considered highly associated with these diseases.  Crohn's disease is discovered to be related to immune disorders particularly .  Different level of cumulative intestinal injuries can cause different complications, such as 'fistulae, damage of bowel function and symptoms reoccur, disability' etc.  The patient group can vary from children to adults. The newest research revealed that immunodeficiency and monogenic are the causes of young patients with inflammatory bowel diseases.  The onset rate keeps updating each year with dramatically increased number and the pathogen of the bowel disease are also complicated due to the complexity of the bowel organs, bowel diseases are diverse in terms of the small and big bowel.
Common symptoms for inflammatory bowel diseases differ by the infection level, but may include severe abdominal pain, diarrhoea, fatigue and unexpected weight loss. Crohn's disease can lead to infection of any part of the digestive tract, including ileum to anus.  Internal manifestations include diarrhoea, abdomen pain, fever, chronic anaemia etc. External manifestations include impact on skin, joints, eyes and liver. Significantly reduced 'microbat diversity' inside the gastrointestinal tract can also be observed. Ulcerative colitis mainly affects the function of the large bowel, and its incidence rate is three times larger than the Crohn's disease.  In terms of clinical features, over 90% of patients exhibited constant diarrhoea, 'rectal bleeding, softer and mucus in the stool, tenesmus and abdomen pain'.  At the same time, patient also reported to be having 'arthralgia, episcleritis and erythema nodosum'.  The symptoms can continue for around 6 weeks or even more than that.
The inflammatory bowel diseases could be effectively treated by 'pharmacotherapies' to relieve and maintain the symptoms, which showed in 'mucosal healing' and symptoms elimination.  However, an optimal therapy for curing both inflammatory diseases are still under research due to the heterogeneity in clinical feature.  Although both UC and CD are sharing similar symptoms, the medical treatment of them are distinctively different.  Dietary treatment can benefit for curing CD by increase the dietary zinc and fish intake, which is related to mucosal healing of the bowel.  Treatments vary from drug treatment to surgery based on the active level of the CD. UC can also be relieved by using immunosuppressive therapy for mild to moderate disease level and application of biological agents for severe cases. 
Irritable bowel syndrome
Irritable bowel syndrome is diagnosed as an intestinal disorder with chronic abdominal pain and inconsistency in form of stool, and is a common bowel disease that can be easily diagnosed in modern society.  The variation in incident rate can be explained by different diagnostic criteria in different countries, with the 18–34 age group being recognized as the high frequency incident group.  The definite cause of irritable bowel syndrome remains a mystery, however it has been found to relate to multiple factors, such as 'alternation of mood and pressure, sleep disorders, food triggers, changing of dysbiosis and even sexual dysfunction'.  One third of irritable bowel syndrome patients has family history with the disease suggesting that genetic predisposition could be a significant cause for irritable bowel syndrome. 
Patients with irritable bowel syndrome commonly experience abdominal pain, changes to stool form, reourrent abdominal bloating and gas,  co-morbid disorders and alternation in bowel habits that caused diarrhea or constipation.  However, anxiety and tension can also be detected, although patients with irritable bowel disease seem healthy. Apart from these typical symptoms, rectal bleeding, unexpected weight loss and increased inflammatory markers require further medical examination and investigation. 
Treatment for irritable bowel disease is multimodal. Dietary intervention and pharmacotherapies can both relieve the symptoms to a certain degree. Avoiding allergic food groups can be beneficial by reducing fermentation in the digestive tract and gas production, hence effectively alleviating abdominal pain and bloating.  Drug interventions, such as laxatives, loperamide,  and lubiprostone  are applied to relieve intense symptoms including diarrhea, abdominal pain and constipation. Psychological treatment, dietary supplements  and gut-focused hypnotherapy  are recommended for targeting depression, mood disorders and sleep disturbance.
Bowel obstruction is a bowel condition which is a blockage that can be found in both the small intestines and large intestines. Increase of contractions can relieve blockages, however, continuous contractions with decreasing functionality may lead to terminated mobility of the small intestines, which then forms the obstruction. At the same time, the lack of contractility encourages liquid and gas accumulation.  and 'electrolyte disturbances'.  Small bowel obstruction can result in severe renal damage and hypovolemia.  while evolving into 'mucosal ischemia and perforation'.  Patients with small bowel obstruction were found to experience constipation, strangulation and abdominal pain and vomiting.  Surgical intervention is primarily used to cure severe small bowel obstruction condition. Nonoperative therapy included ‘nasogastric tube decompression', 'water-soluble-contrast medium process' or symptomatic management can be applied to treat less severe symptoms 
According to research, large bowel obstruction is less common than small bowel obstruction, but is still associated with a high mortality rate.  Large bowel obstruction, also known as colonic obstruction, includes acute colonic obstruction, where a blockage is formed in the colon. Colonic obstructions frequently occur within the elder population, often accompanied by significant 'comorbidities'.  Although colonic malignancy is revealed as the major cause of the colonic obstruction, 'volvulus' has also been founded as a secondary common cause around the world.  In addition, lower mobility, unhealthy mentality and restricted living environment are also listed as risk factors. Surgery and colonic stent placements are widely applied for curing colonic obstructions. 
Attempting forced expiration of breath against a closed airway (the valsalva maneuver) is sometimes practiced to induce defecation while on a toilet. This contraction of expiratory chest muscles, diaphragm, abdominal wall muscles, and pelvic diaphragm exerts pressure on the digestive tract. Ventilation at this point temporarily ceases as the lungs push the chest diaphragm down to exert the pressure. Cardiac arrest  and other cardiovascular complications  can in rare cases occur due to attempting to defecate using the valsalva maneuver. Valsalva retinopathy is another pathological syndrome associated with the Valsalva maneuver.   Thoracic blood pressure rises and as a reflex response the amount of blood pumped by the heart decreases. Death has been known to occur in cases where defecation causes the blood pressure to rise enough to cause the rupture of an aneurysm or to dislodge blood clots (see thrombosis). Also, in releasing the Valsalva maneuver blood pressure falls this, coupled with standing up quickly to leave the toilet, can result in a blackout. [ citation needed ]
Open defecation is the human practice of defecating outside (in the open environment) rather than into a toilet. People may choose fields, bushes, forests, ditches, streets, canals or other open space for defecation. They do so because either they do not have a toilet readily accessible or due to traditional cultural practices.  The practice is common where sanitation infrastructure and services are not available. Even if toilets are available, behavior change efforts may still be needed to promote the use of toilets.
Open defecation can pollute the environment and cause health problems. High levels of open defecation are linked to high child mortality, poor nutrition, poverty, and large disparities between rich and poor.  ( p11 )
Ending open defecation is an indicator being used to measure progress towards the Sustainable Development Goal Number 6. Extreme poverty and lack of sanitation are statistically linked. Therefore, eliminating open defecation is thought to be an important part of the effort to eliminate poverty. 
Anal cleansing after defecation
The anus and buttocks may be cleansed after defecation with toilet paper, similar paper products, or other absorbent material. In many cultures, such as Hindu and Muslim, water is used for anal cleansing after defecation, either in addition to using toilet paper or exclusively. When water is used for anal cleansing after defecation, toilet paper may be used for drying the area afterwards. Some doctors and people who work in the science and hygiene fields have stated that switching to using a bidet as a form of anal cleansing after defecation is both more hygienic and more environmentally friendly. 
Mythology and tradition
Some peoples have culturally significant stories in which defecation plays a role. For example:
8 Things Your Breasts Might Be Trying To Tell You
Are your breasts trying to get your attention, but you're just not listening? You may only pay attention to your breasts when you're either really cold or about to start your period — well, and during sexytimes, of course. There are actually things your breasts are trying to tell you that can be pretty important, though. Specifically, pain in your breasts can be a good barometer for you overall health believe it or not, breast pain can signal anything from hormone changes to arthritis to cancer. On the other hand, your breasts could just be telling you that you need to improve your posture, ease up on your workouts, or get a better bra. No matter what the reason, ongoing breast pain isn't something you should ignore.
The most common type of breast pain is cyclical breast pain, or pain, swelling, and tenderness that worsens during certain points in your menstrual cycle, according to the The Society of Obstetricians and Gynaecologists of Canada. That type of breast pain can usually be alleviated with birth control pills or pain relievers and a heating pad. While you should talk to your doctor about it, it's usually nothing to stress about. Non-cyclical breast pain and breast wall pain are the two other types, and they're usually they types associated with more serious health conditions. Your yearly breast exam is a great time to talk to your doctor about breast health. It could be that the girls are trying to tell you something specific, such as one of the points below.
1. You Drink Too Much Caffeine
Science is mixed about the link between caffeine and breast health. Even though according to The Society of Obstetricians and Gynaecologists of Canada, decreasing caffeine intake can sometimes help reduce swelling in breasts even though, scientists have found no direct link between breast pain and caffeine. Still, it's worth a try if you really can't figure out what's wrong.
2. You're Not Getting Enough Support
According to the Doctor Susan Love Research Foundation for Breast Health, bras that both don't fit well and don't offer good support can lead to breast problems, especially breast pain. A good-fitting bra should not ride up your back, cut into your shoulders, squish your breasts or fit too loosely.
3. Your Thyroid Is Out Of Whack
Hypothyroidism, or an underactive thyroid, sometimes presents as breast tenderness, according to Thyroid.org. You are more likely to also experience symptoms such as weight gain, menstrual irregularities, skin changes, and fatigue.
4. You're Exercising Too Hard
One in three women experience breast soreness or tenderness related to exercise, according to Women's Health. For some women, it's a result of a too-vigorous workout routine. Most of the time, however, it's just related to improper breast support. If your workout routine involves a lot of breast bouncing, make sure you have a sports bra that can take the heat.
5. You Have A Nutritional Deficiency
According to the Doctor Susan Love Research Foundation for Breast Health, increasing your intake of vitamin B6, vitamin B1, and vitamin E may offer relief for breast pain. Sutter Health recommends breast pain patients take calcium and Vitamin E supplements. Talk to your doctor before you start adding these or any other supplements to your diet.
6. You Have Arthritis
Arthritis in your boobs? It sounds odd, I know. But if you have sharp or burning pain in your breasts or in your breastbone area, you could have a form of arthritis known as costochondritis, according to U.S. News & World Report. This pain can feel like a heart attack or injury, as well, and is usually chronic. It's linked to bad posture, so listen to your mom when she tells you to sit up straight.
7. You Eat Too Much Salt
For some women, high salt intake causes water retention, which can lead to breast pain and swelling. according to Sutter Health, which recommends cutting back on salt and increasing water intake to alleviate symptoms. Takeout Chinese food and processed foods in cans and packages tend to be high in sodium. Basically all of the best foods. But all things in moderation.
8. You Have A More Serious Underlying Health Problem
According to the U.S. National Library of Medicine, there are more than a dozen serious health problems that have breast-related symptoms. These health problems range from mastitis, an infection of the breast tissue, to breast cancer.
While your breast pain could just be cyclical, or the common type that accompanies your menstrual cycle, prolonged or intense breast pain isn't something you should ever ignore, as it could be your body's way of telling you that you need to make some changes or seek medical treatment. So don't ignore your breasts when they're trying to get your attention!
Osteomalacia (Vitamin D deficiency)
Vitamin D deficiency is probably more common than once suspected — at least 1 in 20 people in the lowest estimates,18 and possibly many more.19 Vitamin D deficiency can cause subtle widespread pain that may be misdiagnosed as fibromyalgia and/or chronic fatigue syndrome. Most notably for the purposes of this article, it can cause bone aching, particularly in the back, that is worse at night (for no clear reason). Naturally, any night pain that doesn’t actually wake you up is often noticed upon waking.
This symptom is caused by osteomalacia, which is bone weakening from malfunctioning bone building biology. The Mayo Clinic describes osteomalacia symptoms like so: “The dull, aching pain associated with osteomalacia most commonly affects the lower back, pelvis, hips, legs and ribs. The pain may be worse at night, or when you’re putting weight on affected bones.”
Other symptoms of vitamin D deficiency include: fatigue and weakness, lower pain threshold, and more acute soreness after exercise that is slower to resolve, sweating, and depression. For more information, see Vitamin D for Pain.
Why you should NEVER drink water standing up
There is nothing like water to quench your thirst. It plays a key role in keeping you hydrated and just so you know, there are a lot many health problems and other related illnesses (and even weight issues) which can be solved if you just keep up with the intake of water on a regular basis. For ideal health, it is important that you have at least 8 glasses of water every day.
02 /9 Here is why you should NOT stand and drink water!
We all have the habit of getting home and drinking water right away, often standing. Since we all believe that there is nothing wrong that water can do, we don't give it a though how we are having it - standing or sitting. Well, wake up to the reality. When you have water standing up, you don't get the required nutrition. Shocked? Water, if not consumed in the right manner, can be very bad for you and put you at risk of potential health problems.
03 /9 This is what Ayurveda says
According to Ayurveda, our bodies are designed in a way so that we get maximum benefits when we sit down and exercise our body. That is why, there is a reason why our elders have always told us to sit down and eat and do the same while we drink water!
04 /9 Consume it the right way
There is actually a right way to have water to detoxify the body and gain all the nutrients and minerals. It is important to remember that our body, though made up of 70% water, loses so much of it everyday, it is crucial to fill up on the quantity and hence, it matters that you consume it the RIGHT WAY. And no, it cannot be achieved when you stand up and drink! Wondering why? We tell you.
05 /9 Slow down!
When you drink water standing up, the water which goes in passes through the system with a straight gush, not really reaching the organs where it is supposed to do the job. Hence, the impurities which are supposed to go out get deposited in the kidneys and the bladder. Wellness coach and fitness enthusiast Nikita Parmar also shared a post which highlighted some of the dangers of standing up and drinking water.
06 /9 Don't trigger the nerves!
Standing up and drinking water makes the body out of sync with nature and triggers the nervous system, making it feel it is facing danger. The nutrients really go waste this way and your body is bound to face stress or any tension.
07 /9 It doesn't really quench your thirst!
And worst, drinking water this way doesn&rsquot actually quench your thirst. Since the water goes directly through, the requires nutrients and vitamins don&rsquot reach the liver and digestive tract. This is because when you stand and drink water, it travels through the system really fast and you risk your lungs and heart functions. The oxygen levels also get disturbed this way.
08 /9 How you drink water affects your posture
This, in turn, can also put bones and joints at risk as the water gushes down the body. You can also experience joint pain, bone degeneration and weakness. Thus, the speed of chugging water down and how you drink it has an important role to play.
09 /9 Drink your water sitting down!
Hence, there is a very valid reason to sit down and gulp your water, the same way it is recommended that you sit down and have your meal. Our bodies are designed in a way that you get maximum health benefits when you sit down and keep your back erect. When you drink your water from a bottle or a glass sitting down, the nutrients reach the brain and boost its activity. It also aids better digestion this way and ensures that you don&rsquot feel bloated after having water. Drinking water this way passes through the regular designed track and ensures all the benefits are achieved in the organs. Toxins go away, impurities are flushed out and your health improves overall!
- Harper’s Illustrated Biochemistry, 31 st Edition.USGS.Archivedfrom the original on 9 July 2017. Retrieved 27 June 2017.
- Reece, Jane B. (31 October 2013). Campbell Biology (10 ed.).Pearson. p. 48.ISBN9780321775658.
- Ball, Philip (2008).“Water: Water—an enduring mystery”. Nature.452(7185): 291–2.Bibcode:2008Natur.452..291B.doi:10.1038/452291a.PMID18354466
- Kotz, J.C., Treichel, P., & Weaver, G.C. (2005). Chemistry & Chemical Reactivity. Thomson Brooks/Cole.ISBN978-0-534-39597-1.