Does diverticular disease cause blood in stool?

Diverticular pouches can bleed from small blood vessels in the bowel wall. The blood may look bright red or darker depending on where it comes from and how quickly it passes. Bleeding may occur with or without abdominal discomfort, so the absence of pain does not explain its cause.

Rectal bleeding can also result from haemorrhoids, anal fissures, inflammation, polyps, or other bowel conditions. A clinician may ask about the colour and amount, recurrence, bowel habit, pain, dizziness, and medicines such as blood thinners. Do not assume a familiar diagnosis without review, particularly when bleeding is new or recurring.

Contact a clinician for advice about any unexplained blood in stool. Note its appearance, when it happened, whether it was mixed through the stool or on the paper, and any related symptoms. Bring a medicine list, especially if you use anticoagulants or antiplatelet treatment. Do not stop prescribed medicines unless a clinician directs you.

Seek emergency help for heavy or ongoing bleeding, black tar-like stool, fainting, marked dizziness, a rapid heartbeat, severe abdominal pain, fever with weakness, or confusion. Urgent assessment is also needed when bleeding recurs or occurs with vomiting or a swollen abdomen. These signs can indicate substantial blood loss or another serious bowel problem.

Ask what may be causing the bleeding, whether blood tests or bowel investigations are needed, how medicines affect risk, and which changes require immediate help.