An electron micrograph of rotavirus, the cause of nearly 40% of hospitalizations from diarrhea in children under five.[1]
ICD-10 A09, K59.1
ICD-9 787.91
DiseasesDB 3742
MedlinePlus 003126
eMedicine ped/583
MeSH D003967

Diarrhea or diarrhoea (from the Ancient Greek διάρροια from διά dia "through" and ῥέω rheo "flow") is the condition of having at least three loose or liquid bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin with loss of the normal stretchiness of the skin and changes in personality. This can progress to decreased urination, loss of skin color, a fast heart rate, and a decrease in responsiveness as it becomes more severe. Loose but non watery stools in babies who are breastfed, however, may be normal.[2] The most common cause is an infection of the intestines due to either a virus, bacteria, parasite, or a condition known as gastroenteritis. These infections are often acquired from food or water that has been contaminated by stool, or directly from another person who is infected. It may be divided into three types: short duration watery diarrhea, short duration bloody diarrhea, and if it lasts for more than two weeks, persistent diarrhea. The short duration watery diarrhea may be due to an infection by cholera. If blood is present it is also known as dysentery.[2] A number of non-infectious causes may also result in diarrhea including: hyperthyroidism, lactose intolerance, inflammatory bowel disease, a number of medications, and irritable bowel syndrome among other.[3] In most cases stool cultures are not required to confirm the exact cause.[4] Prevention of infectious diarrhea is by improved sanitation, clean drinking water, and hand washing. Breastfeeding for at least six months is also recommended as is vaccination against rotavirus. Oral rehydration solution (ORS), which is clean water with modest amounts of salts and sugar, along with zinc tablets are the treatments of choice.[2] This treatment has been estimated to have saved 50 million children in the past 25 years.[1] When people have diarrhea it is recommended that they continue to eat healthy food and babies continue to be breastfeed.[2] If commercial ORS are not available, homemade solutions may be used.[5] In those with severe dehydration, intravenous fluids may be required.[2] Most cases; however, can be managed well with fluids by mouth.[6] Antibiotics, while rarely used, may be recommended in a few cases such as those who have bloody diarrhea and a high fever, those with severe diarrhea following travelling, and those who grow specific bacteria or parasites in their stool.[4] Loperamide may help decrease the number of bowel movement but is not recommended in those with severe disease.[4] About 1.7 to 5 billion cases of diarrhea occur per year.[2][3] It is most common in developing countries, where young children get diarrhea on average three times a year.[2] Worldwide, as of 2012, it is the second most common cause of deaths in children younger than five (0.76 million or 11%).[2][7] Frequent episodes of diarrhea are also a common cause of malnutrition and the most common cause in those younger than five years of age.[2] Other long term problems that can result include poor physical and intellectual development.[7]


  • Definition 1
    • Secretory 1.1
    • Osmotic 1.2
    • Exudative 1.3
    • Inflammatory 1.4
    • Dysentery 1.5
  • Differential diagnosis 2
    • Infections 2.1
    • Malabsorption 2.2
    • Inflammatory bowel disease 2.3
    • Irritable bowel syndrome 2.4
    • Other causes 2.5
  • Pathophysiology 3
    • Evolution 3.1
  • Diagnostic approach 4
  • Prevention 5
  • Management 6
    • Fluids 6.1
    • Eating 6.2
    • Medications 6.3
    • Alternative therapies 6.4
  • Epidemiology 7
  • References 8
  • External links 9


Types 5–7 on the Bristol Stool Chart indicate diarrhea

Diarrhea is defined by the

External links

  1. ^ a b c d e f g h "whqlibdoc.who.int" (PDF).  
  2. ^ a b c d e f g h i "Diarrhoeal disease Fact sheet N°330". World Health Organization. April 2013. Retrieved 18 June 2014. 
  3. ^ a b Doyle, edited by Basem Abdelmalak, D. John (2013). Anesthesia for otolaryngologic surgery. Cambridge: Cambridge University Press. pp. 282–287.  
  4. ^ a b c d DuPont, HL (Apr 17, 2014). "Acute infectious diarrhea in immunocompetent adults.". The New England journal of medicine 370 (16): 1532–40.  
  5. ^ Prober, edited by Sarah Long, Larry Pickering, Charles G. (2012). Principles and practice of pediatric infectious diseases (4th ed.). Edinburgh: Elsevier Saunders. p. 96.  
  6. ^ ACEP. "Nation’s Emergency Physicians Announce List of Test and Procedures to Question as Part of Choosing Wisely Campaign". Choosing Wisely. Retrieved 18 June 2014. 
  7. ^ a b "Global Diarrhea Burden". CDC. January 24, 2013. Retrieved 18 June 2014. 
  8. ^ "Diarrhoea". World Health Organization. 
  9. ^ "WGO Practice Guideline - Acute diarrhea". Retrieved 9 March 2011. 
  10. ^ a b c "The Basics of Diarrhea". Webmd.com. 17 February 2011. Retrieved 9 March 2011. 
  11. ^ a b c d e f g h i j "The Treatment Of Diarrhea, A manual for physicians and other senior health workers". Sometimes needs to be downloaded twice. See “4.2 Treatment Plan A: home therapy to prevent dehydration and malnutrition,” “4.3 Treatment Plan B: oral rehydration therapy for children with some dehydration,” and “4.4 Treatment Plan C: for patients with severe dehydration” on pages 8 to 16 (12–20 in PDF). See also “8. MANAGEMENT OF DIARRHOEA WITH SEVERE MALNUTRITION” on pages 22–24 (26–30 in PDF) and “ANNEX 2: ORAL AND INTRAVENOUS REHYDRATION SOLUTIONS” on pages 33–37 (37–41 in PDF).  
  12. ^ a b Wilson ME (December 2005). "Diarrhea in nontravelers: risk and etiology". Clin. Infect. Dis. 41 41 (Suppl 8): S541–6.  
  13. ^ Navaneethan U, Giannella RA (November 2008). "Mechanisms of infectious diarrhea". Nature Clinical Practice Gastroenterology & Hepatology 5 (11): 637–47.  
  14. ^ Patel MM, Hall AJ, Vinjé J, Parashar UD (January 2009). "Noroviruses: a comprehensive review". Journal of Clinical Virology 44 (1): 1–8.  
  15. ^ Greenberg HB, Estes MK (May 2009). "Rotaviruses: from pathogenesis to vaccination". Gastroenterology 136 (6): 1939–51.  
  16. ^ Uhnoo I, Svensson L, Wadell G (September 1990). "Enteric adenoviruses". Baillière's Clinical Gastroenterology 4 (3): 627–42.  
  17. ^ Mitchell DK (November 2002). "Astrovirus gastroenteritis". The Pediatric Infectious Disease Journal 21 (11): 1067–9.  
  18. ^ Viswanathan VK, Hodges K, Hecht G (February 2009). "Enteric infection meets intestinal function: how bacterial pathogens cause diarrhoea". Nature Reviews Microbiology 7 (2): 110–9.  
  19. ^ Rupnik M, Wilcox MH, Gerding DN (July 2009). "Clostridium difficile infection: new developments in epidemiology and pathogenesis". Nature Reviews Microbiology 7 (7): 526–36.  
  20. ^ Kiser JD, Paulson CP, Brown C (April 2008). "Clinical inquiries. What's the most effective treatment for giardiasis?". The Journal of Family Practice 57 (4): 270–2.  
  21. ^ Dans L, Martínez E (June 2006). "Amoebic dysentery". Clinical Evidence (15): 1007–13.  
  22. ^ Gonzales ML, Dans LF, Martinez EG (2009). Gonzales, Maria Liza M, ed. "Antiamoebic drugs for treating amoebic colitis". Cochrane Database Syst Rev (2): CD006085.  
  23. ^ Alam NH, Ashraf H (2003). "Treatment of infectious diarrhea in children". Paediatr Drugs 5 (3): 151–65.  
  24. ^ Longstreth GF, Thompson WG, Chey WD, Houghton LA, Mearin F, Spiller RC (2006). "Functional bowel disorders". Gastroenterology 130 (5): 1480–91.  
  25. ^ Wedlake, L; A'Hern, R; Russell, D; Thomas, K; Walters, JR; Andreyev, HJ (2009). "Systematic review: the prevalence of idiopathic bile acid malabsorption as diagnosed by SeHCAT scanning in patients with diarrhoea-predominant irritable bowel syndrome". Alimentary pharmacology & therapeutics 30 (7): 707–17.  
  26. ^ Kasper DL, Braunwald E, Fauci AS, Hauser SL, Longo DL, Jameson JL. Harrison's Principles of Internal Medicine. New York: McGraw-Hill, 2005. ISBN 0-07-139140-1.
  27. ^ Williams, George; Nesse, Randolph M. (1996). Why we get sick: the new science of Darwinian medicine. New York: Vintage Books. pp. 36–38.  
  28. ^ DuPont HL, Hornick RB (December 1973). "Adverse effect of lomotil therapy in shigellosis". JAMA 226 (13): 1525–8.  
  29. ^ Ruuska T, Vesikari T (1990). "Rotavirus disease in Finnish children: use of numerical scores for clinical severity of diarrhoeal episodes". Scand. J. Infect. Dis. 22 (3): 259–67.  
  30. ^ Hempel, S; Newberry, SJ, Maher, AR, Wang, Z, Miles, JN, Shanman, R, Johnsen, B, Shekelle, PG (9 May 2012). "Probiotics for the prevention and treatment of antibiotic-associated diarrhea: a systematic review and meta-analysis". JAMA: the Journal of the American Medical Association 307 (18): 1959–69.  
  31. ^ Ejemot RI, Ehiri JE, Meremikwu MM, Critchley JA (2008). Ejemot, Regina I, ed. "Hand washing for preventing diarrhoea". Cochrane Database Syst Rev (1): CD004265.  
  32. ^ King CK, Glass R, Bresee JS, Duggan C (November 2003). "Managing acute gastroenteritis among children: oral rehydration, maintenance, and nutritional therapy". MMWR Recomm Rep 52 (RR–16): 1–16.  
  33. ^ "BestBets: Does Withholding milk feeds reduce the duration of diarrhoea in children with acute gastroenteritis?". 
  34. ^ a b c Community Health Worker Training Materials for Cholera Prevention and Control, CDC, slides at back are dated 17 November 2010. Page 7 states " . . . Continue to breastfeed your baby if the baby has watery diarrhea, even when traveling to get treatment. Adults and older children should continue to eat frequently."
  35. ^ Schiller LR (2007). "Management of diarrhea in clinical practice: strategies for primary care physicians". Rev Gastroenterol Disord 7 (Suppl 3): S27–38.  
  37. ^ a b Rehydration Project, http://rehydrate.org/ Homemade Oral Rehydration Solution Recipe.
  38. ^ a b "Management of acute diarrhoea and vomiting due to gastoenteritis in children under 5". National Institute of Clinical Excellence. April 2009. 
  39. ^ Webb, A; Starr, M (April 2005). "Acute gastroenteritis in children". Australian family physician 34 (4): 227–31.  
  40. ^ Macgillivray, S; Fahey, T; McGuire, W (31 October 2013). "Lactose avoidance for young children with acute diarrhoea.". The Cochrane database of systematic reviews 10: CD005433.  
  41. ^ Dryden MS, Gabb RJ, Wright SK (June 1996). "Empirical treatment of severe acute community-acquired gastroenteritis with ciprofloxacin". Clin. Infect. Dis. 22 (6): 1019–25.  
  42. ^ a b de Bruyn G (2008). "Diarrhoea in adults (acute)". Clin Evid (Online) 2008: 0901.  
  43. ^ Wong CS, Jelacic S, Habeeb RL, Watkins SL, Tarr PI (June 2000). "The risk of the hemolytic-uremic syndrome after antibiotic treatment of Escherichia coli O157:H7 infections". N. Engl. J. Med. 342 (26): 1930–6.  
  44. ^ "Diarrhoeal Diseases". World Health Organization. February 2009. 
  45. ^ DuPont HL, Ericsson CD, Farthing MJ et al. (2009). "Expert review of the evidence base for self-therapy of travelers' diarrhea". J Travel Med 16 (3): 161–71.  
  46. ^ Pawlowski SW, Warren CA, Guerrant R (May 2009). "Diagnosis and treatment of acute or persistent diarrhea". Gastroenterology 136 (6): 1874–86.  
  47. ^ Lazzerini, M; Ronfani, L (Jan 31, 2013). "Oral zinc for treating diarrhoea in children.". The Cochrane database of systematic reviews 1: CD005436.  
  48. ^ Allen SJ, Martinez EG, Gregorio GV, Dans LF (2010). Allen, Stephen J, ed. "Probiotics for treating acute infectious diarrhoea". Cochrane Database Syst Rev 2010 (11): CD003048.  
  49. ^ Kale-Pradhan PB, Jassal HK, Wilhelm SM (February 2010). "Role of Lactobacillus in the prevention of antibiotic-associated diarrhea: a meta-analysis". Pharmacotherapy 30 (2): 119–26.  
  50. ^ "Mortality and Burden of Disease Estimates for WHO Member States in 2004" (xls).  
  51. ^ Mandell, Gerald L.; Bennett, John E.; Dolin, Raphael (2004). Mandell's Principles and Practices of Infection Diseases (6th ed.). Churchill Livingstone.  


World wide in 2004 approximately 2.5 billion cases of diarrhea occurred which results in 1.5 million deaths among children under the age of five.[1] Greater than half of these were in Africa and South Asia.[1] This is down from a death rate of 4.5 million in 1980 for gastroenteritis.[51] Diarrhea remains the second leading cause of infant mortality (16%) after pneumonia (17%) in this age group.[1]

Disability-adjusted life year for diarrhea per 100,000 inhabitants in 2004.[50]
  no data
  < 500
  > 6000


Probiotics reduce the duration of symptoms by one day and reduced the chances of symptoms lasting longer than four days by 60%.[48] The probiotic lactobacillus can help prevent antibiotic associated diarrhea in adults but possibly not children.[49] For those who with lactose intolerance, taking digestive enzymes containing lactase when consuming dairy products often improves symptoms.

Zinc supplementation benefits children with diarrhea in developing countries, but only in infants over six months old. This supports the World Health Organisation guidelines for zinc, but not in the very young.[47]

Alternative therapies

Bile acid sequestrants such as cholestyramine can be effective in chronic diarrhea due to bile acid malabsorption. Therapeutic trials of these drugs are indicated in chronic diarrhea if bile acid malabsorption cannot be diagnosed with a specific test, such as SeHCAT retention.

While bismuth compounds (Pepto-Bismol) decreased the number of bowel movements in those with travelers' diarrhea, they do not decrease the length of illness.[45] Anti motility agents like loperamide are also effective at reducing the number of stools but not the duration of disease.[4] These agents should only be used if bloody diarrhea is not present.[46]

While antibiotics are beneficial in certain types of acute diarrhea, they are usually not used except in specific situations.[41][42] There are concerns that antibiotics may increase the risk of hemolytic uremic syndrome in people infected with Escherichia coli O157:H7.[43] In resource poor countries, treatment with antibiotics may be beneficial.[42] However, some bacteria are developing antibiotic resistance, particularly Shigella.[44] Antibiotics can also cause diarrhea, and antibiotic-associated diarrhea is the most common adverse effect of treatment with general antibiotics.


WHO recommends a child with diarrhea continue to be fed. Continued feeding speeds the recovery of normal intestinal function. In contrast, children whose food is restricted have diarrhea of longer duration and recover intestinal function more slowly. A child should also continue to be breastfed. The WHO states "Food should never be withheld and the child's usual foods should not be diluted. Breastfeeding should always be continued."[11] And in the specific example of cholera, CDC also makes the same recommendation.[34] In young children who are not breast-fed and live in the developed world, a lactose free diet may be useful to speed recovery.[40]


Drinks especially high in simple sugars, such as soft drinks and fruit juices, are not recommended in children under 5 years of age as they may increase dehydration. A too rich solution in the gut draws water from the rest of the body, just as if the person were to drink sea water.[11][38] Plain water may be used if more specific and effective ORT preparations are unavailable or are not palatable.[38] Additionally, a mix of both plain water and drinks perhaps too rich in sugar and salt can alternatively be given to the same person, with the goal of providing a medium amount of sodium overall.[11] A nasogastric tube can be used in young children to administer fluids if warranted.[39]

Vomiting often occurs during the first hour or two of treatment with ORS, especially if a child drinks the solution too quickly, but this seldom prevents successful rehydration since most of the fluid is still absorbed. WHO recommends that if a child vomits, to wait five or ten minutes and then start to give the solution again more slowly.[11]

Appropriate amounts of supplemental zinc and potassium should be added if available. But the availability of these should not delay rehydration. As WHO points out, the most important thing is to begin preventing dehydration as early as possible.[11] In another example of prompt ORS hopefully preventing dehydration, CDC recommends for the treatment of cholera continuing to give Oral Rehydration Solution during travel to medical treatment.[34]

Oral rehydration solution (ORS) can be used to prevent dehydration. Standard home solutions such as salted rice water, salted yogurt drinks, vegetable and chicken soups with salt can be given. Home solutions such as water in which cereal has been cooked, unsalted soup, green coconut water, weak tea (unsweetened), and unsweetened fresh fruit juices can have from half a teaspoon to full teaspoon of salt (from one-and-a-half to three grams) added per liter. Clean plain water can also be one of several fluids given.[11] There are commercial solutions such as Pedialyte, and relief agencies such as UNICEF widely distribute packets of salts and sugar. A WHO publication for physicians recommends a homemade ORS consisting of one liter water with one teaspoon salt (3 grams) and two tablespoons sugar (18 grams) added[11] (approximately the "taste of tears"[36]). Rehydration Project recommends adding the same amount of sugar but only one-half a teaspoon of salt, stating that this more dilute approach is less risky with very little loss of effectiveness.[37] Both agree that drinks with too much sugar or salt can make dehydration worse.[11][37]

A person consuming oral rehydration solution.


Medications such as loperamide (Imodium) and bismuth subsalicylate may be beneficial; however they may be contraindicated in certain situations.[35]

In many cases of diarrhea, replacing lost fluid and salts is the only treatment needed. This is usually by mouth – oral rehydration therapy – or, in severe cases, intravenously.[1] Diet restrictions such as the BRAT diet are no longer recommended.[32] Research does not support the limiting of milk to children as doing so has no effect on duration of diarrhea.[33] To the contrary, WHO recommends that children with diarrhea continue to eat as sufficient nutrients are usually still absorbed to support continued growth and weight gain and that continuing to eat speeds also recovery of normal intestinal functioning.[11] CDC recommends that children and adults with cholera also continue to eat.[34]


Probiotics decrease the risk of diarrhea in those taking antibiotics.[30] In institutions and in communities, interventions that promote hand washing lead to significant reductions in the incidence of diarrhea.[31]

A rotavirus vaccine decrease the rates of diarrhea in a population.[1] New vaccines against rotavirus, Shigella, ETEC, and cholera are under development, as well as other causes of infectious diarrhea.


A severity score is used to aid diagnosis in children.[29]

  • In infants
  • Moderate or severe diarrhea in young children
  • Associated with blood
  • Continues for more than two days
  • Associated non-cramping abdominal pain, fever, weight loss, etc.
  • In travelers
  • In food handlers, because of the potential to infect others;
  • In institutions such as hospitals, child care centers, or geriatric and convalescent homes.

The following types of diarrhea may indicate further investigation is needed:

Diagnostic approach

According to two researchers, Williams, diarrhea may function as an evolved expulsion defense mechanism. As a result, if it is stopped, there might be a delay in recovery.[27] They cite in support of this argument research published in 1973 which found that treating Shigella with the anti-diarrhea drug (Co-phenotrope, Lomotil) caused people to stay feverish twice as long as those not so treated. The researchers indeed themselves observed that: "Lomotil may be contraindicated in shigellosis. Diarrhea may represent a defense mechanism".[28]



Other causes

Another possible cause of diarrhea is irritable bowel syndrome (IBS) which usually presents with abdominal discomfort relieved by defecation and unusual stool (diarrhea or constipation) for at least 3 days a week over the previous 3 months.[24] Symptoms of diarrhea-predominant IBS can be managed through a combination of dietary changes, soluble fiber supplements, and/or medications such as loperamide or codeine. About 30% of patients with diarrhea-predominant IBS have bile acid malabsorption diagnosed with an abnormal SeHCAT test.[25]

Irritable bowel syndrome

  • Ulcerative colitis is marked by chronic bloody diarrhea and inflammation mostly affects the distal colon near the rectum.
  • Crohn's disease typically affects fairly well demarcated segments of bowel in the colon and often affects the end of the small bowel.

The two overlapping types here are of unknown origin:

Inflammatory bowel disease

Causes include:

Malabsorption is the inability to absorb food fully, mostly from disorders in the small bowel, but also due to maldigestion from diseases of the pancreas.


Other infectious agents such as parasites and bacterial toxins also occur.[12] In sanitary living conditions where there is ample food and a supply of clean water, an otherwise healthy person usually recovers from viral infections in a few days. However, for ill or malnourished individuals, diarrhea can lead to severe dehydration and can become life-threatening.[23]

Parasites do not often cause diarrhea except for the protozoan Giardia, which can cause chronic infections if these are not diagnosed and treated with drugs such as metronidazole,[20] and Entamoeba histolytica.[21][22]

In the elderly, particularly those who have been treated with antibiotics for unrelated infections, a toxin produced by Clostridium difficile often causes severe diarrhea.[19]

Campylobacter spp. are a common cause of bacterial diarrhea, but infections by Salmonella spp., Shigella spp. and some strains of Escherichia coli are also a frequent cause.[18]

There are many causes of infectious diarrhea, which include viruses, bacteria and parasites.[13] Norovirus is the most common cause of viral diarrhea in adults,[14] but rotavirus is the most common cause in children under five years old.[15] Adenovirus types 40 and 41,[16] and astroviruses cause a significant number of infections.[17]


Chronic diarrhea can be the part of the presentations of a number of chronic medical conditions affecting the intestine. Common causes include ulcerative colitis, Crohn's disease, microscopic colitis, celiac disease, irritable bowel syndrome and bile acid malabsorption.

Diarrhea is most commonly due to viral gastroenteritis with rotavirus, which accounts for 40% of cases in children under five.[1] (p. 17) In travelers however bacterial infections predominate.[12] Various toxins such as mushroom poisoning and drugs can also cause acute diarrhea.

Diagram of the human gastrointestinal tract.

Differential diagnosis

If there is blood visible in the stools, it is also known as dysentery. The blood is trace of an invasion of bowel tissue. Dysentery is a symptom of, among others, Shigella, Entamoeba histolytica, and Salmonella.


Inflammatory diarrhea occurs when there is damage to the mucosal lining or brush border, which leads to a passive loss of protein-rich fluids and a decreased ability to absorb these lost fluids. Features of all three of the other types of diarrhea can be found in this type of diarrhea. It can be caused by bacterial infections, viral infections, parasitic infections, or autoimmune problems such as inflammatory bowel diseases. It can also be caused by tuberculosis, colon cancer, and enteritis.


Exudative diarrhea occurs with the presence of blood and pus in the stool. This occurs with inflammatory bowel diseases, such as Crohn's disease or ulcerative colitis, and other severe infections such as E. coli or other forms of food poisoning.[10]


Osmotic diarrhea occurs when too much water is drawn into the bowels. If a person drinks solutions with excessive sugar or excessive salt, these can draw water from the body into the bowel and cause osmotic diarrhea.[11] Osmotic diarrhea can also be the result of maldigestion (e.g., pancreatic disease or Coeliac disease), in which the nutrients are left in the lumen to pull in water. Or it can be caused by osmotic laxatives (which work to alleviate constipation by drawing water into the bowels). In healthy individuals, too much magnesium or vitamin C or undigested lactose can produce osmotic diarrhea and distention of the bowel. A person who has lactose intolerance can have difficulty absorbing lactose after an extraordinarily high intake of dairy products. In persons who have fructose malabsorption, excess fructose intake can also cause diarrhea. High-fructose foods that also have a high glucose content are more absorbable and less likely to cause diarrhea. Sugar alcohols such as sorbitol (often found in sugar-free foods) are difficult for the body to absorb and, in large amounts, may lead to osmotic diarrhea.[10] In most of these cases, osmotic diarrhea stops when offending agent (e.g. milk, sorbitol) is stopped.


Secretory diarrhea means that there is an increase in the active secretion, or there is an inhibition of absorption. There is little to no structural damage. The most common cause of this type of diarrhea is a cholera toxin that stimulates the secretion of anions, especially chloride ions. Therefore, to maintain a charge balance in the lumen, sodium is carried with it, along with water. In this type of diarrhea intestinal fluid secretion is isotonic with plasma even during fasting.[10] It continues even when there is no oral food intake.


[9] Acute diarrhea is defined as an abnormally frequent discharge of semisolid or fluid fecal matter from the bowel, lasting less than 14 days, by