Ulcerative colitis is a chronic inflammatory bowel disease (IBD) in which inflammation and ulcers develop in the inner lining of the large intestine. The disease begins in the rectum and may extend through part or all of the colon. Symptoms often occur in flares, with periods of remission between them.
Symptoms
Common symptoms include diarrhea, blood in the stool, rectal bleeding, abdominal pain or cramping, urgency to have a bowel movement and a feeling that the bowel has not emptied completely. More active disease may cause fatigue, fever, anemia, loss of appetite or weight loss. Children may have problems with growth and development.
Diagnosis
A healthcare professional will review symptoms, medical and family history and perform an examination. Blood tests and stool tests can look for anemia, inflammation and infection. Endoscopy of the large intestine, usually colonoscopy or flexible sigmoidoscopy with biopsies, is used to confirm the diagnosis and assess the extent of inflammation.
Treatment
Treatment aims to reduce inflammation, bring on remission and maintain remission. Medicines may include aminosalicylates, corticosteroids for selected flares, immunomodulators, biologic medicines and other targeted therapies. The choice depends on how much of the colon is affected, disease severity, previous treatment and individual health factors.
Surgery to remove the colon can cure the intestinal disease and may be required for severe disease, complications, precancerous changes or symptoms that cannot be controlled with medicines.
Long-term monitoring
Long-standing ulcerative colitis can increase the risk of colorectal cancer, particularly when a larger part of the colon is affected. People with ulcerative colitis may therefore need regular colonoscopy surveillance according to their individual risk and duration of disease.
Food and nutrition
No single diet causes or cures ulcerative colitis. A balanced diet is important, although symptoms during a flare may make eating difficult. Nutritional deficiencies should be identified and treated. Discuss major dietary restrictions or supplements with a healthcare professional or registered dietitian.
When to seek medical care
Arrange medical assessment for persistent diarrhea, blood in the stool, recurring abdominal pain, unexplained weight loss or ongoing fatigue. People with diagnosed ulcerative colitis should contact their healthcare team when symptoms worsen or treatment is no longer controlling the disease.
Urgent warning signs
Seek urgent medical care for heavy rectal bleeding, severe or rapidly worsening abdominal pain, a markedly swollen abdomen, high fever, repeated vomiting, fainting, severe dehydration or rapidly worsening illness. Severe ulcerative colitis can cause complications such as toxic megacolon or bowel perforation.
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Sources
Last reviewed: 4 September 2026.
Medical disclaimer: This information is general and does not replace individual medical assessment, diagnosis or treatment.