Causes of Chronic (Prolonged, Persistent, Constant) Diarrhea

Definition of Chronic Diarrhea

Diarrhea (frequent loose bowel movements) is considered as chronic when it lasts for more than 2 weeks (1). Below is a list of main causes of chronic diarrhea with typical symptoms.

Common Causes of Chronic Diarrhea

Unlike sudden (acute) diarrhea, chronic diarrhea is mostly of non-infectious origin:

  • Irritable bowel syndrome (IBS) appears with alternating diarrhea and constipation, abdominal pains, triggered by stress or certain foods and relieved by bowel movement. Diagnosis is made after exclusion of other bowel disorders.
  • Inlactose intolerance, diarrhea and bloating appear within hours after ingesting dairy or other products containing lactose.Diagnosis is made by a breath test with lactose
  • Infood allergies, tingling lips, itchy throat or skin or diarrhea may appear within few minutes or, in delayed response, within several hours after ingestion of allergenic food. Antihistamine pill usually bring relief in few hours
  • In fructose malabsorption, diarrhea and abdominal bloating appear within 48 hours after a meal rich in fructose or sorbitol. Diagnosis is made by a breath test with fructose. Toddler’s diarrhea may appear in small children fed with large amounts of fruit juices.
  • Intestinal parasites , including intestinal worms, mostly cause mild diarrhea with waxing and waning course, abdominal bloating, mucus, blood or parts of intestinal worms in the stool. Weight loss is common. Giardia may cause sulphur smelling gas.
  • Inflammatory bowel disease (IBD): Crohn’s disease and ulcerative colitis may appear with low grade fever, fatigue, nausea, lower left or lower righ abdominal pain, skin rash, diarrhea. Diagnosis is made by colonoscopy.
  • Inceliac disease, diarrhea appear within hours after ingesting gluten-containing foods (wheat, rye or barley). Diagnosis can be made if symptoms cease after gluten-free diet and is confirmed by investigation of a sample of duodenal mucosa.
  • Liver disease, like cirrhosis or chronic hepatitis, may appear withupper right abdominal pain, jaundice, swollen abdomen, fatigue and diarrhea.
  • Gallbladder disease typically presents with cramping pain below the right ribs, appearing within an hour after the meal. White diarrhea appears if bile ducts are blocked.
  • Acute or chronic pancreatitis and pancreatic cancer appear withupper middle (or upper left or right) abdominal pain. White bowel movements/diarrhea appears in developed disease.
  • Diverticulitis appears withpain in lower left abdomen, bloating, fever and diarrhea.
  • Small intestinal bacterial overgrowth (SIBO)may be due reduced small intestinal motility in diabetes or partial bowel obstruction or may appear together with fructose malabsorption or lactose intolerance. Abdominal bloating, early satiety, excessive burping and gas (sometimes with sulphur smell) and, sometimes, diarrhea are main symptoms. Diagnosis is with breath test with lactulose.
  • In alcoholism, diarrhea is usually caused by liver or pancreatic disease and malnutrition. Weight loss is typical.
  • Malnutritionresults from insufficient nutrient or calorie intake in starvation or intestinal malabsorption. It is common in children in poor areas and in alcoholics. Obvious underweight, fatigue, diarrhea and pale skin due to anemia are typical symptoms.
  • Medications, like antibiotics, laxatives (if abused), anti-acid drugs with magnesium, some drugs for treating  high-pressure and other drugs or remedies (read leaflets!) may cause chronic diarrhea.

Rare Causes of Chronic Diarrhea

Rare causes of chronic diarrhea include diabetes, chronic infections and poisoning, ischemic colitis, systemic sclerosis, hormonal disorders, cancer, kidney failure, short bowel syndrome, inborn diseases, and paradoxical diarrhea in constipated children.

Related Articles:


  1. Definition of chronic diarrhea
About Jan Modric (249 Articles)
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