Consider microscopic colitis in older adults presenting with chronic, non-bloody, watery diarrhoea

Microscopic colitis is a common but under-recognised and underdiagnosed cause of chronic diarrhoea that typically occurs in older adults, especially women. It is an inflammatory bowel disease that is at least as common as Crohn’s disease and ulcerative colitis, and easily mistaken for irritable bowel syndrome. The hallmark symptom is usually chronic, non-bloody, watery diarrhoea. Diagnosis involves colonoscopy with biopsies, and the drug of choice is oral budesonide.