Short-term diarrhea
The symptom of diarrhea is usually a bowel infection (gastroenteritis), which may result from:
- Viruses – such as rotavirus or norovirus
- Bacteria – such as Escherichia coli (E. coli), campylobacter, Clostridium difficile (C. difficile), salmonella or shigella; all of these could result in food poisoning.
- Parasites – Giardiasis can be caused by Giardia intestinal parasites.
Long-term diarrhea
Conditions that can cause persistent diarrhea include:
- Irritable bowel syndrome (IBS) – a disorder affecting the normal function of the bowels that is poorly understood
- Inflammatory bowel disease – diseases that cause inflammation of the gut, including Ulcerative colitis and Crohn’s disease
- Coeliac disease – a digestive condition that can have an adverse reaction to gluten
- Bile acid malabsorption – a buildup of bile in the digestive system caused by liver production
- Chronic pancreatitis – Pancreatic inflammation
- Diverticular disease – occurs when the lining of the intestine develops small bulges or pockets
- Bowel cancer – this may cause diarrhea and blood in your stool
Persistent diarrhea can also be experienced sometimes after gastrectomy surgery on the stomach. This is an operation that can be used as a treatment for stomach cancer – for example, to remove part of the stomach.