Diarrhea, or diarrhea, is a pathological condition manifested by frequent (more than 3 times a day) watery stools, which are often accompanied by painful urge and anal incontinence. According to the World Health Organization (WHO), diarrhea, or rather dehydration and malnutrition caused by it, is one of the causes of death in children under 5 years of age.

General information and classification


According to the duration of symptoms, diarrhea can be:

  • acute (<14 days);
  • persistent (14-30 days);
  • chronic (> 30 days).

By origin – infectious and non-infectious. Infectious diarrhea, in turn, can be:

  • viral (for example, with rotavirus infection);
  • bacterial (salmonellosis);
  • caused by protozoa (amoebic dysentery).

By the mechanism of occurrence:

  • secretory (when more fluid is released in the intestinal lumen than is absorbed, and due to the growing intestine, motility increases);
  • osmolar (when substances in the intestinal lumen that “attract” water and irritate the intestinal wall are undigested carbohydrates, bile acids, undigested fats);
  • exudative (the intestinal lumen secretes an inflammatory secret – exudate);
  • dyskinetic (intestinal motility is impaired due to altered nervous or hormonal regulation).

Strictly speaking, diarrhea is not a disease, a symptom that can appear in various diseases, both infectious and not at all related to the gastrointestinal tract. For example, high blood glucose levels caused by intestinal damage can be one of the causes of chronic diarrhea. Therefore, you should not diagnose and treat diarrhea on your own – the doctor will determine the cause faster and more accurately.

Diarrhea causes


The most common cause of diarrhea is infection. The infectious agent can enter the body through food or water contaminated with faeces. The same group should include diarrhea caused by parasitic invasion (giardiasis, enterobiasis, ascariasis).

Of the non-infectious causes of diarrhea, indigestion is in the first place. It may be a congenital intolerance to certain foods, among which the most famous are lactose and gluten intolerance. Either a digestive disorder occurs due to a chronic disease of the gastrointestinal tract. For example, a deficiency in pancreatic enzymes causes undigested fats to irritate the intestinal wall, which in turn provokes diarrhea.

Also, diarrhea can be caused by chronic non-infectious bowel pathology, for example, irritable bowel syndrome, ulcerative colitis, Crohn’s disease. Finally, it can be caused by diseases that are not related to the gastrointestinal tract. Above, diabetic enteropathy has already been mentioned, in which, due to a high level of glucose in the blood, the normal innervation (nervous regulation) of the intestine is disrupted. Diarrhea in hyperthyroidism, hypoparathyroidism, chronic cardiovascular or renal failure, vasculitis can be distinguished into the same group. Diarrhea not associated with gastrointestinal tract pathologies can also include the well-known “bear disease”.

Diarrhea caused by medication should be distinguished into a separate group. Most often, it is caused by the uncontrolled intake of laxatives in order to lose weight. But digitalis preparations, cytostatics, immunosuppressants can also provoke excessive intestinal activity.