Digestive

Medicines for Microscopic colitis

A cause of chronic watery diarrhoea in which the bowel looks normal but is inflamed under the microscope — usually controlled with specific medicines and by removing triggers.

Education and reference only. This explains which medicines are used and why, in plain language — it deliberately contains no doses and is not a substitute for advice from your doctor or pharmacist. Always discuss your own treatment with a qualified clinician, and check the BNF and the product labelling for prescribing detail.

Quick answer

What is Microscopic colitis?

Microscopic colitis is a condition that causes ongoing or recurrent watery, non-bloody diarrhoea, often with urgency, tummy cramps and sometimes weight loss. Its distinguishing feature is that the lining of the bowel looks normal during a colonoscopy, but samples (biopsies) examined under the microscope show inflammation — which is why the diagnosis can be missed unless biopsies are taken.

  • How it is treated: Treatment aims to control the diarrhoea and improve quality of life.
  • Self-care: Stopping smoking, reviewing possible trigger medicines with a doctor, staying hydrated, and identifying any dietary factors that worsen symptoms can all help manage microscopic colitis.
  • When to seek help: See a GP for persistent watery diarrhoea, especially with weight loss, or diarrhoea that wakes you at night.

What it is

Microscopic colitis is a condition that causes ongoing or recurrent watery, non-bloody diarrhoea, often with urgency, tummy cramps and sometimes weight loss. Its distinguishing feature is that the lining of the bowel looks normal during a colonoscopy, but samples (biopsies) examined under the microscope show inflammation — which is why the diagnosis can be missed unless biopsies are taken. It is more common in older adults, particularly women, and is sometimes linked to certain medicines, smoking, and autoimmune conditions. Though it can be troublesome, it does not carry the same risks as some other bowel diseases.

How it is treated

Treatment aims to control the diarrhoea and improve quality of life. A first step is reviewing and, where possible, stopping any medicines that may be contributing, and stopping smoking. Many people respond well to a specific steroid medicine that acts mainly in the bowel, used as a course and sometimes as maintenance, and anti-diarrhoeal treatment can help milder symptoms. The condition can come and go, and long-term outlook is generally good. Care is usually guided by a gastroenterologist, with follow-up to manage relapses.

For this condition, these medicines

Medicine classes used for Microscopic colitis

Each links to a full, dose-free guide — what it is, how it works, who can and cannot use it, side effects, interactions and FAQs.

Beyond medication

Lifestyle and self-care

Stopping smoking, reviewing possible trigger medicines with a doctor, staying hydrated, and identifying any dietary factors that worsen symptoms can all help manage microscopic colitis.

When to get help

When to see a doctor

See a GP for persistent watery diarrhoea, especially with weight loss, or diarrhoea that wakes you at night. Report any blood in the stool, which needs assessment as it is not typical of this condition.

999Emergency — call 999 or go to A&E
111Urgent advice — call NHS 111 or use 111 online
GPNon-urgent — see your GP or pharmacist

Not sure how urgent it is? It is always OK to call NHS 111 for advice, day or night.

Answers

Microscopic colitis: frequently asked questions

Why is it called "microscopic" colitis?

Because the bowel lining looks normal during a colonoscopy, and the inflammation is only seen when tissue samples are examined under a microscope — so biopsies are needed to diagnose it.

Is microscopic colitis serious?

It can cause troublesome diarrhoea but does not carry the same risks as some other bowel diseases, and it usually responds well to treatment. The long-term outlook is generally good.

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