Table 1.

Causes of chronic diarrhoea

CommonInfrequentRare
Functional bowel disorders (including IBS-diarrhoea)
Bile acid diarrhoea
Dietary related
Colonic neoplasia
Inflammatory bowel disease: ulcerative colitis, Crohn’s disease and microscopic colitis
Coeliac disease
Drug causes
Overflow diarrhoea
Small bowel bacterial overgrowth
Mesenteric ischaemia
Lymphoma
Chronic pancreatitis
Surgical causes: small bowel resections, faecal incontinence, internal fistulae etc
Radiation enteropathy
Pancreatic carcinoma
Endocrine causes: hyperthyroidism, diabetes, hypoparathyroidism and Addison's
Giardiasis (and other chronic infection)
Other small bowel enteropathies: Whipple’s disease, tropical sprue, amyloid, intestinal lymphangiectasia etc
Autonomic neuropathy
Hormone secreting tumours: VIPoma, gastrinoma and carcinoid
Factitious diarrhoea
  • Adapted from BSG 2018. 2 IBS = irritable bowel syndrome; VIPoma = vasoactive intestinal peptide tumour.