When to worry about blood in stool with an anal fissure

An anal fissure is a small tear in the skin at the anus. Passing a hard stool can reopen it, causing sharp pain during or after a bowel movement and a small amount of bright red blood on paper or the outside of stool.

Bleeding that is mixed throughout the stool, black or tar-like, recurrent without pain, or accompanied by abdominal symptoms deserves a separate assessment. These features can point away from a simple fissure.

Keep stools soft by drinking enough fluid for your needs and adding fibre gradually if it suits you. Avoid straining or delaying the urge to open your bowels. A warm shallow bath can soothe discomfort, while prescribed ointments may relax the anal muscle and help the tear heal.

Arrange a review if pain or bleeding is not settling, or if fissures keep returning. A clinician can check for constipation, inflammatory bowel disease, infection, or another source of bleeding.

Seek urgent care for heavy bleeding, dizziness or fainting, black stool, severe or spreading pain, fever, pus, a rapidly growing painful lump, or inability to pass stool or urine. Get prompt advice if you take blood-thinning medicine or have a condition that affects immunity.

Ask how to soften your stool, how long to use any prescribed treatment, and whether an examination is needed. Discuss recurrent tears, persistent bleeding, or pain that continues after bowel movements.