Lymphocytic colitis and collagenous colitis on one page. An inflammatory bowel disease, not Crohn’s or ulcerative colitis. Community experiences, not medical advice.
Microscopic colitis (MC) is an inflammatory bowel disease. Guts UK is explicit about that. It is not Crohn’s disease and it is not ulcerative colitis. It is also not “mild UC”. The lining of the colon usually looks normal to the eye at colonoscopy. The inflammation is only clear when a pathologist looks at biopsies under a microscope.
This page covers both recognised subtypes together, because symptoms and first-line treatment are shared:
Guts UK notes it is more often diagnosed in middle age, more often in women, and can be missed for years because it is mistaken for IBS or diverticular disease. Guts UK figures we can quote: about 1 in 2,000 people in the UK have microscopic colitis (likely an underestimate); about 1 in 10 people labelled IBS-D may have MC; and in people aged 65 and over with diarrhoea, as many as 1 in 5 might have it. A BJGP 2021 practice guide states that coeliac disease is present in 3–4% of people with MC.
Diagnosis needs multiple biopsies from different parts of the colon, including both sides, examined under a microscope.
A normal faecal calprotectin does not exclude microscopic colitis. Guts UK states that the calprotectin test cannot show signs of MC, and that CRP and ESR may also be normal or only slightly raised. A reassuring stool or blood test is not an all-clear.
People with microscopic colitis should be tested for coeliac disease, because both can be present (BJGP 2021: coeliac disease in 3–4% of people with MC).
NIDDK also says the colon lining most often looks normal at colonoscopy, and that the diagnosis is made when a pathologist examines biopsies under a microscope — the same "camera can look fine" point already on this page. NIDDK, Diagnosis of Microscopic Colitis. https://www.niddk.nih.gov/health-information/digestive-diseases/microscopic-colitis/diagnosis
Guts UK lists associations with some NSAIDs, proton pump inhibitors, certain antidepressants (for example sertraline), statins, and other drug classes. That is background for a conversation with the prescribing clinician. Do not stop PPIs, NSAIDs, SSRIs, or any other regular medicine because you read it here. Stopping some of those drugs without advice can be harmful. If a medicine is thought to be relevant, your doctor can weigh alternatives with you.
Microscopic colitis is specialist-diagnosed. Do not start or stop steroids or IBD-family medicines because of this page.
Anecdotal themes, not outcomes data:
UK sources on this page are Guts UK, BJGP, Crohn's & Colitis UK, BSG and NHS. NIDDK and AGA 2016 sit behind the biopsy diagnosis and budesonide already described here.
Patient information on lymphocytic and collagenous colitis, biopsy diagnosis, and why stool tests can miss it.
Visit ResourcePractice guide noting coeliac disease in 3–4% of people with microscopic colitis.
Visit ResourceCharity information for the wider IBD family, including microscopic colitis.
Visit ResourceBritish Society of Gastroenterology education and guidance on microscopic colitis.
Visit ResourceNHS overview of IBD. Microscopic colitis sits in this family, separate from Crohn’s and ulcerative colitis.
Visit ResourceThe National Institute of Diabetes and Digestive and Kidney Diseases describes microscopic colitis as an inflammatory bowel disease. Doctors can only see the inflammation by looking at colon tissue under a microscope. It names the same two types already on this page — lymphocytic colitis and collagenous colitis — and says they share symptoms and treatment.
Visit ResourceThe American Gastroenterological Association 2016 guideline recommends budesonide to induce remission in symptomatic microscopic colitis — the US twin of Guts UK's usual first medicine already listed here, not a new steroid and not a dose to copy from a webpage.
PubMed PMID 26584605Community experiences, not medical advice. This page is for education only. It is not a diagnosis, treatment plan, or substitute for care from a qualified clinician. Always discuss tests, medicines, and diet changes with your GP or specialist.