Diverticulitis and ulcerative colitis: what should you know?

Diverticulitis is inflammation in one or more pouches that form in the bowel wall. Ulcerative colitis is a longer-term inflammatory condition affecting the lining of the large bowel and rectum. Their symptoms can overlap, including abdominal pain, diarrhoea, urgency and changes in bowel habit. The pattern, duration, blood or mucus, examination findings and test results help a clinician separate them from infection and other causes.

Arrange a GP consultation for persistent diarrhoea, recurring pain, blood or mucus in stool, unexplained tiredness, or a change that is unusual for you. Write down stool frequency, urgency, nighttime symptoms, food changes, medicines and recent travel. Do not stop prescribed bowel medicines without advice. A clinician may decide whether blood tests, stool tests or specialist assessment are appropriate.

Seek urgent medical care for heavy bleeding, severe or rapidly worsening abdominal pain, repeated vomiting, a swollen abdomen, high fever, faintness, confusion or inability to keep fluids down. Someone already diagnosed with ulcerative colitis should follow their flare plan and seek help if symptoms are more severe than expected or fail to settle.

Ask which features suggest diverticulitis, ulcerative colitis or another cause, which tests are needed, how to manage medicines during diarrhoea, and whether screening or specialist follow-up is relevant to you.