How common is blood in stool in diverticular disease?

Diverticular disease refers to small pouches that can form in the bowel wall. Bleeding may occur when a blood vessel near a pouch is affected. It can be painless and may be bright red or darker red. Diverticular disease may also be present without bleeding. Blood in stool is not specific to diverticular disease, so a clinician considers the pattern, associated symptoms and your medical history before deciding on tests.

Make an appointment for a new episode of bleeding, even if it settles. Record whether blood is seen in the bowl, on toilet paper, or mixed with stool, and mention constipation, diarrhoea, pain, fever, dizziness or a change in bowel habit. Bring a list of medicines, particularly medicines that affect clotting or irritate the stomach and bowel. A clinician can decide whether examination or bowel investigations are needed.

Call for urgent help if there is a large amount of blood, repeated bleeding, clots, collapse, faintness, chest discomfort, breathlessness, black tar-like stool, or severe abdominal pain. Seek prompt review as well if bleeding is accompanied by fever, worsening tenderness, or difficulty passing stool or gas.

Ask whether the bleeding pattern is compatible with diverticular disease, what other causes are being considered, which medicines may matter, and when follow-up should occur. If you have had prior bowel imaging or a bowel examination, tell the clinician when and what it found.