Chronic Diarrhea

There are many causes of chronic diarrhea; these may be different for children and adults. Causes can be grouped into two categories: diarrhea caused by an infection and diarrhea not caused by an infection. Sometimes, the cause of chronic diarrhea remains unknown.

Infection

Diarrhea caused by an infection may result from the following:

• Parasites, such as Cryptosporidium parvum, Cyclospora cayetanensis, Entamoeba histolytica, Giardia lamblia, or Microsporidia
• Bacteria, such as Campylobacter, Clostridium difficile, Escherichia coli, Listeria monocytogenes, Salmonella enteritidis, or Shigella
• Viral infections, such as rotavirus, HIV, or Norwalk agent

Other Causes

Diarrhea not caused by an infection may result from the following:

• Antibiotics
• High blood pressure medications
• Cancer drugs
• Crohn's disease
• Colitis
• Diabetes, thyroid, and other endocrine diseases
• Food additives (sorbitol, fructose, and others)
• Food allergies
• Previous surgery or radiation of the abdomen or gastrointestinal tract
• Tumors
• Reduced blood flow to the intestine
• Heredity—certain diseases occur more often in related family members.
• Travel