This site is intended for healthcare professionals

Go to /sign-in page

You can view 5 more pages before signing in

Collagenous colitis

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

Microscopic colitis syndrome is defined by the triad of:

  • chronic watery diarrhoea
  • normal mucosal appearance on colonoscopy
  • characteristic histological changes in the mucosal biopsy

  • chronic watery diarrhoea
    • most common symptom in microscopic colitis is chronic, non-bloody, watery, diarrhoea, frequently associated with faecal urgency, the passage of stools at night, and faecal incontinence
    • may also complain of cramping abdominal pain
  • microscopic colitis affects 0.12% of the population
  • Coeliac disease is present in 3%–4% of patients with microscopic colitis, reflecting an overlap with other autoimmune conditions
  • median age at diagnosis is 60 years of age
  • risk factors include:
    • smoking
    • long-term use of proton-pump inhibitors, non-steroidal anti-inflammatory drugs, and selective serotonin reuptake inhibitors
  • diagnosis:
    • depends on characteristic histological findings
    • normal mucosal appearance on colonoscopy - 4.77% of patients with normal colonoscopy findings have microscopic colitis confirmed on histology from biopsies
    • characteristic histological changes in the mucosal biopsy:
      • lymphocytic infiltration in the lamina propria - when this is marked the disease may be termed lymphocytic colitis
      • variable thickening of the subepithelial collagen layer - when fibrosis is marked the disease may be termed collagenous colitis


  • Barrett K.Microscopic colitis: a guide for general practice British Journal of General Practice 2021; 71: 41–42. DOI:

Related pages

Create an account to add page annotations

Add information to this page that would be handy to have on hand during a consultation, such as a web address or phone number. This information will always be displayed when you visit this page