Rectal bleeding can refer to any blood that passes from your anus, although rectal bleeding is usually assumed to refer to bleeding from your lower colon or rectum. Your rectum makes up the lower portion of your large intestine. The bleeding may result in bright red blood in the stool as well as maroon colored or black stool. The bleeding also may be occult (not visible with the human eye). The common causes of rectal bleeding from the colon include anal fissure, hemorrhoids, diverticulosis, colon cancer and polyps, colonic polyp removal, angiodysplasias. Make an appointment to see your doctor if you have rectal bleeding that lasts more than 1 or 2 days, or earlier if the bleeding worries you. Most people who have rectal bleeding dont have cancer or another serious illness, but its important to have it checked out. The tests for rectal bleeding depend on your age, symptoms and medical history. Common causes of bleeding from the anus include constipation, anal fissures, and hemorrhoids. Rectal bleeding may stem from many conditions, including hemorrhoids, anal fissures, anal abscesses or fistulas, diverticulosis, diverticulitis, inflammatory bowel disease, ulcers, polyps, or. Bleeding from the bottom (rectal bleeding) a small amount of one-off bleeding from the bottom is not usually a serious problem. A small tear in your anus (anal fissure) bleeding with or without lumps, itching or pain sexually transmitted infections. If bleeding is associated with an already diagnosed medical condition, a doctor will discuss ways to manage, reduce, and track symptoms. However, heavier bleeding could be a sign of an underlying condition or injury that may require medical attention.