Microscopic colitis: a guide for general practice

INTRODUCTION

Irritable bowel syndrome (IBS) affects 10%–20% of the population¹ but other conditions have similar symptoms. Microscopic colitis is a cause of chronic, non-bloody, watery diarrhoea, particularly in older patients in whom the impact on quality of life can be significant. Microscopic colitis affects 0.12% of the population but 12.80% of those with unexplained chronic, watery diarrhoea. The median age at diagnosis is 60,² reflecting an older population than those typically diagnosed with other types of inflammatory bowel disease. Risk factors include smoking and long-term use of proton-pump inhibitors, non-steroidal anti-inflammatory drugs, and selective serotonin reuptake inhibitors, although a causal relationship has not been established.²