Ulcerative colitis in the sigmoid colon: what to know

The sigmoid colon is the curved lower part of the large intestine before the rectum. Inflammation there may lead to frequent small bowel movements, a strong urge to go, mucus or blood, and discomfort low in the abdomen. Symptoms can come and go as flare-ups and quieter periods. The location helps a clinician plan assessment, but symptoms alone cannot confirm the diagnosis; infections, haemorrhoids and other bowel problems can cause similar changes.

Arrange a GP consultation if bowel changes, rectal bleeding or cramping persist. Keep a simple record of stool frequency, blood or mucus, pain, fever, appetite and any medicines. Drink regularly, choose foods you tolerate, and do not stop prescribed treatment without medical advice. A clinician may review your history, examine your abdomen, request stool or blood tests, and decide whether specialist bowel assessment is needed.

Seek urgent medical help for heavy or ongoing rectal bleeding, severe or worsening abdominal pain, a swollen abdomen, repeated vomiting, faintness, confusion, or signs of dehydration such as very little urine. Contact a clinician promptly if diarrhoea is rapidly increasing, fever accompanies a flare, or you cannot keep fluids down.

Ask which tests can distinguish ulcerative colitis from infection, whether the inflammation appears limited to the sigmoid colon, how to recognise a flare, and which treatment plan fits your symptoms and other medicines.