Inflammatory bowel disease (IBD) is long-term inflammation of the gut. The two main types are:
- Ulcerative colitis, which affects the lining of the large bowel (colon) and rectum
- Crohn's disease, which can affect any part of the gut from mouth to anus, most often the end of the small bowel, and can involve the full thickness of the bowel wall
IBD usually starts in young adults, but can begin at any age. It has become more common in Singapore and across Asia. It is different from irritable bowel syndrome (IBS), which does not cause inflammation.
Symptoms
- Diarrhoea lasting more than a few weeks, often waking you at night
- Blood or mucus in the stool, and an urgent need to go
- Abdominal pain, weight loss, tiredness or fever
- Anaemia or low iron (see iron deficiency anaemia)
- In Crohn's disease, painful swelling or a discharging opening near the anus (abscess or fistula)
- Sometimes joint pain, red eyes or skin rashes
Tests
- Blood and stool tests: to look for inflammation, anaemia and infection, including a stool calprotectin test
- Colonoscopy with biopsies: to see the inflammation, take samples and examine the end of the small bowel
- Scans such as MRI or CT of the small bowel, and sometimes capsule endoscopy
- Ruling out infections, including intestinal tuberculosis, which can look very similar to Crohn's disease
Treatment
The aim is to control symptoms and heal the lining of the bowel, which lowers the risk of flares, complications and surgery. Treatment is chosen for the type, extent and severity of the disease, and may include:
- Anti-inflammatory medicines such as mesalazine, mainly for ulcerative colitis
- Short courses of steroids to settle a flare
- Immune-suppressing medicines, such as azathioprine
- Biologic and other targeted medicines for moderate to severe disease
- Surgery for complications or disease that does not respond to medicine
Long-term care
- Regular reviews and blood tests, with blood tests or stool tests to check that the bowel stays healed
- Surveillance colonoscopy for colorectal cancer, usually starting about eight years after colitis begins
- Vaccinations, bone health checks, and stopping smoking, which especially helps Crohn's disease
- Planning ahead for pregnancy, as most IBD medicines can be continued safely
Seek urgent care at an emergency department for frequent bloody diarrhoea with fever or a fast heartbeat, severe abdominal pain or swelling, or signs of dehydration.
General information only. Reviewed by Dr Chia Chung King, 2026-11-07. Book a consultation.