Why does diverticular disease cause blood in stool?

Bleeding from a diverticulum can show as red or dark-red blood in the toilet, on the stool, or on toilet paper. It may occur with little discomfort, although diverticular inflammation can cause pain and fever. Blood in Stool is a common presentation of Diverticular Disease, but blood can also come from other parts of the digestive tract or from conditions around the anus.

The amount and colour of blood do not reliably establish the cause. A healthcare professional may need to assess your symptoms, medicines, medical history, and whether tests are appropriate.

Contact a clinician promptly whenever you notice blood in stool, even if it stops. Make a note of the colour, amount, whether it was mixed with stool, and associated symptoms such as pain, fever, dizziness, or a change in bowel habit. Tell the clinician about medicines that can affect bleeding, including prescribed and non-prescribed products.

Do not assume the bleeding is from known diverticular disease. Assessment can identify whether it is likely related and whether treatment or further investigation is needed.

Seek emergency help for heavy or ongoing bleeding, black tar-like stool, fainting, severe dizziness, chest discomfort, shortness of breath, confusion, or severe abdominal pain. These symptoms can indicate significant blood loss or another urgent problem.

Ask what may be causing the bleeding, whether you need blood tests or bowel investigations, which medicines to review, and what changes should lead you to seek urgent help.