Colon
General
Diarrhea / dysentery
Author: Hanni Gulwani, M.B.B.S.
Last author update: 1 May 2013
Last staff update: 22 December 2021
Copyright: 2003-2025, PathologyOutlines.com, Inc.
PubMed Search: colitis dysentery
Table of Contents
Definition / general | Terminology | Epidemiology | Clinical features | Diagrams / tables | Microscopic (histologic) description | Additional referencesCite this page: Gulwani H. Diarrhea / dysentery. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/colondiarrheageneral.html. Accessed April 2nd, 2025.
Definition / general
- Normal intestines receive 9 liters of fluid per day (oral intake: 2 L, saliva: 1L, gastric juices: 2L, pancreatic juices: 2L, intestinal juices: 1L); most is reabsorbed in small intestine and colon
Terminology
- Diarrhea: 3 or more loose stools / day; also increase in stool mass, fluidity or frequency of defecation (Wikipedia: Diarrhea [Accessed 22 December 2021], eMedicine: Diarrhea [Accessed 22 December 2021])
- Chronic diarrhea: decrease in stool consistency for more than 4 weeks (Am Fam Physician 2011;84:1119, Best Pract Res Clin Gastroenterol 2012;26:551, Arch Pathol Lab Med 2013;137:83)
- Secretory diarrhea: > 500 mL of fluid stool per day, isotonic with plasma, persists during fasting
- Dysentery: low volume, painful, bloody diarrhea (Wikipedia: Dysentery [Accessed 22 December 2021])
- Exudative disease: purulent bloody stools, persists with fasting - due to bacteria (Salmonella, Shigella, Campylobacter), Entamoeba histolytica, idiopathic inflammatory bowel disease, typhlitis
- Malabsorption: bulky stools, abates with fasting, due to defective intraluminal digestion, primary mucosal cell abnormalities, reduced small bowel surface area, lymphatic obstruction, Giardia lamblia
Epidemiology
- 12,000 deaths/year from dehydration in developing countries - 50% of all deaths before age 5
- Affects 40% of U.S. population - #2 in attack rates in U.S. after common cold
Clinical features
Deranged motility:
- Improper gut neuromuscular function causes decreased transit time
- Due to surgical resection of gut, irritable bowel syndrome (neural dysfunction), hyperthyroidism, diabetic neuropathy, carcinoid syndrome
- Decreased motility due to small bowel diverticula, blind loop, bacterial overgrowth
- Purulent bloody stools, persist with fasting; caused by bacteria (Salmonella, Shigella, Campylobacter), Entamoeba histolytica, idiopathic inflammatory bowel disease, typhlitis (neutropenic colitis in immunosuppressed)
- Bulky stools, abates with fasting; caused by defective intraluminal digestion, primary mucosal cell abnormalities, reduced small intestinal surface area, lymphatic obstruction, Giardia lamblia (MedlinePlus: Malabsorption [Accessed 22 December 2021], Wikipedia: Malabsorption [Accessed 22 December 2021])
- Gut luminal solutes create high stool osmolality, abates with fasting
- Stool osmolality > electrolyte concentration by 50 mOsm
- Associated with lactase deficiency, lactulose therapy, gut lavage, antacids, primary bile acid malabsorption
- > 500 mL of fluid stool per day, isotonic with plasma, persists during fasting
- Infectious (viral damage to epithelium): rotavirus, Norwalk virus, enteric adenoviruses, calicivirus, astrovirus
- Infectious (enterotoxin): Vibrio cholera, E. coli, Bacillus cereus, Clostridium perfringens
- Neoplastic: tumor production of peptides, villous adenoma in distal colon
- Excessive laxatives
Diagrams / tables
Images hosted on other servers:
Chronic diarrhea
Microscopic (histologic) description
- Patchy lesions with variable villus abnormality, rarely severe
- Increased chronic and acute inflammatory infiltrate in epithelium and lamina propria
- Small intestinal bacterial overgrowth: common cause of chronic diarrhea and malabsorption with either villous blunting or normal duodenal biopsy (Arch Pathol Lab Med 2010;134:264)
Additional references
