Overview of microscopic colitis.

Microscopic colitis encompasses both collagenous and lymphocytic colitis and is a relatively common condition with rising incidence. Diagnosis is by colonoscopy (which is usually normal but may show some mild changes) and biopsies which reveal characteristic histological findings. Symptoms include non-bloody diarrhoea with urgency which may be associated with faecal incontinence and abdominal pain. Microscopic colitis is associated with a reduced health-related quality of life, and treatment is aimed at symptom control. Medications linked with the development of microscopic colitis, including proton pump inhibitors, non-steroidal anti-inflammatory drugs and selective serotonin-reuptake inhibitors, should be discontinued. If symptoms persist, budesonide is a licensed treatment for microscopic colitis which has been shown to be effective in clinical trials and real-world practice.