Ulcerative colitis

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Last reviewed: 16 Oct 2025

Last updated: 14 Nov 2025

Ulcerative colitis (UC) is a type of inflammatory bowel disease characterized by diffuse inflammation of the colonic mucosa and a relapsing, remitting course.

Patients commonly experience bloody diarrhea, chronic diarrhea (or both), lower abdominal pain, fecal urgency, and extraintestinal manifestations, particularly those related to activity of the colitis.

Diagnosis requires endoscopy with biopsy and negative stool culture.

Relapses are often associated with pathogens; therefore, stool should be obtained for culture in all cases of disease flare-up.

Treatment aims to induce and maintain remission. Drug choice and formulation depends on the severity and extent of disease.

Toxic megacolon can occur with associated risk of perforation. Bowel adenocarcinoma is a complication in 3% to 5% of patients.

Definition

UC is a type of inflammatory bowel disease that characteristically involves the rectum and extends proximally to affect a variable length of the colon. It is recognized as a multifactorial polygenic disease, as the exact etiology is still unknown. Included in the etiologic theories are environmental factors, immune dysfunction, and a likely genetic predisposition.[1][2][3]

This topic covers the diagnosis and treatment of ulcerative colitis in adults.

History and exam

Key diagnostic factors

rectal bleeding
diarrhea
blood in stool

Full details

Other diagnostic factors

abdominal pain
arthritis and spondylitis
malnutrition
abdominal tenderness
fever
weight loss
constipation
skin rash
uveitis and episcleritis
pallor

Full details

Risk factors

family history of inflammatory bowel disease
human leukocyte antigen-B27
infection
use of nonsteroidal anti-inflammatory drugs (NSAIDs)
not smoking or former smoker

Full details

Diagnostic tests

1st tests to order

stool studies for infective pathogens
fecal calprotectin (FC)
CBC
comprehensive metabolic panel (including LFTs)
erythrocyte sedimentation rate (ESR)
CRP
plain abdominal radiograph
flexible sigmoidoscopy
colonoscopy
biopsies

Full details

Tests to avoid

serologic antibody testing

Full details

Tests to consider

CT scan
intestinal ultrasound

Full details

Treatment algorithm

ACUTE

acute severe ulcerative colitis (UC)

moderate-to-severe disease

mild disease

ONGOING

disease in remission

Contributors

Authors

Andrew Poullis, BSc, MBBS, MD, FRCP

Consultant Gastroenterologist

Department of Gastroenterology

St George’s Hospital

London

Disclosures

AP is an author of a reference cited in this topic.

Sailish Honap, MBChB (Hons), MRes, MRCP (UK)

Consultant Gastroenterologist

Department of Gastroenterology

St George’s Hospital

London

Disclosures

SH has received honoraria from Pfizer (speaker, consultant, advisory board member, and received travel grants), Janssen (speaker fees, travel grants), AbbVie (speaker fees, consultant, travel grants), Takeda (speaker fees), Ferring (travel grants), Pharmacosmos (travel grants), Galapagos (travel grants).

Kamal Patel,

Disclosures

all disclosures

Aaron Bhakta, BMedSci (Hons), BMBS, MSc, MRCP

Clinical Fellow in Gastroenterology

Department of Gastroenterology

St George’s Hospital

London

Disclosures

AB declares that he has no competing interests.

Acknowledgements

Dr Hesam A. Nooredinvand, and Dr Andrew Poullis would like to gratefully acknowledge Dr Ben Shandro, Dr Anet Soubieres, Dr Rhys Hewett, Dr Willem J.S. de Villiers, and Dr Houssam Mardini, previous contributors to this topic.

Disclosures

BS, AS, RH, WJSD, and HM declare that they have no competing interests.

Peer reviewers

Stephen B Hanauer, MD

Professor of Medicine

Gastroenterology and Hepatology

Northwestern University

Evanston

Disclosures

SW declares that he has no competing interests.

Peer reviewer acknowledgements

BMJ Best Practice topics are updated on a rolling basis in line with developments in evidence and guidance. The peer reviewers listed here have reviewed the content at least once during the history of the topic.

Disclosures

Peer reviewer affiliations and disclosures pertain to the time of the review.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

World Gastroenterology Organisation. Global guidelines: inflammatory bowel disease. Aug 2015 [internet publication].Full text

Rubin DT, Ananthakrishnan AN, Siegel CA, et al. ACG clinical guideline update: ulcerative colitis in adults. Am J Gastroenterol. 2025 Jun 3;120(6):1187-224.Full text Abstract

Moran GW, Gordon M, Sinopolou V, et al. British Society of Gastroenterology guidelines on inflammatory bowel disease in adults: 2025. Gut. 2025 Jun 23;74(Suppl 2):s1-101.Full text Abstract

Singh S, Loftus EV Jr, Limketkai BN, et al. AGA living clinical practice guideline on pharmacological management of moderate-to-severe ulcerative colitis. Gastroenterology. 2024 Dec;167(7):1307-43.Full text Abstract

Harbord M, Eliakim R, Bettenworth D, et al. Third European evidence-based consensus on diagnosis and management of ulcerative colitis. Part 2: current management. J Crohns Colitis. 2017 Jul 1;11(7):769-84.Full text Abstract

National Institute for Health and Care Excellence (UK). Ulcerative colitis: management. May 2019 [internet publication].Full text

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

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Ulcerative colitis

Summary

Definition

History and exam

Key diagnostic factors

Other diagnostic factors

Risk factors

Diagnostic tests

1st tests to order

Tests to avoid

Tests to consider

Treatment algorithm

acute severe ulcerative colitis (UC)

moderate-to-severe disease

mild disease

disease in remission

Contributors

Authors

Andrew Poullis, BSc, MBBS, MD, FRCP

Disclosures

Sailish Honap, MBChB (Hons), MRes, MRCP (UK)

Disclosures

Kamal Patel,

Disclosures

Aaron Bhakta, BMedSci (Hons), BMBS, MSc, MRCP

Disclosures

Acknowledgements

Disclosures

Peer reviewers

Stephen B Hanauer, MD

Disclosures

Peer reviewer acknowledgements

Disclosures

References

Key articles

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

Differentials

Guidelines

Patient information

Videos

Log in or subscribe to access all of BMJ Best Practice

Log in or subscribe to access all of BMJ Best Practice

Log in to access all of BMJ Best Practice