Rectal Bleeding

Bleeding from the rectum is not normal. Many patients with rectal bleeding blame the blood on hemorrhoids, and in many instances this is the case. In some patients, however, rectal bleeding can be a symptom of a far more worrisome problem. Considering the possible causes of rectal bleeding will help you and your physician decide what tests need to be performed to find the cause.


Hemorrhoids – These are dilated blood vessels that can be located outside the rectum, or inside where you neither see nor feel them. When outside the rectum, they look like small purple grapes and can be felt as small bumps. They may develop with chronic straining to pass stools or pregnancy. Your doctor may be able to see external hemorrhoids during a simple rectal exam, but the internal hemorrhoids must be visualized in a more advanced manner. Treatment usually involves softening the stool, thus lessening straining with stool passage.

Fissure – This is a small tear in the canal where stool is passed from the rectum. Usually bleeding is accompanied by pain when the stool moves past the tear. Your doctor may be able to diagnose this problem with a simple digital rectal exam. Most fissures heal spontaneously, but local creams, sitz baths, and stool softeners can be helpful.

Fistula – This is an abnormal connection between your colon and skin. The most common cause is ulcerating disease in the colon, namely Crohn’s disease. Ulcers in the colon burrow deep through the colon walls, through the soft tissues around the colon, and eventually open up a passage to the skin. Fistulas drain pus, mucous, stool, and sometimes blood. Fistulas are usually a marker of significant problems within the colon and require evaluation. They can be healed with antibiotics, treatment for Crohn’s disease, or surgery.

Colitis/Proctitis – These are general terms meaning inflammation within the colon and rectum, respectively. Inflammation can be in the form of swelling of the colon walls, redness, or ulcers. Along with rectal bleeding, other symptoms include abdominal pain and diarrhea. The most common causes of colitis and proctitis are ulcerative colitis and Crohn’s disease. Other causes of colitis include poor blood flow to the colon (ischemic colitis), infections, NSAID ulcerations (anti-inflammatory medications), and sliding of the rectal tissue in and out of the rectum resulting in ulcer formation.

Diverticulosis – Not to be confused with diverticulitis, which is an infection of a diverticulum, diverticulosis is the presence of small sacs projecting from the colon. These sacs can spontaneously bleed. Most bleeding diverticula stop bleeding spontaneously, but sometimes the bleeding can be life threatening. The diagnosis is made by colonoscopy or radiologic testing.

Polyps and colorectal cancer – These are by far the most worrisome causes of rectal bleeding. Polyps are benign growths that can bleed. Treatment of polyps is imperative, not only to prevent blood loss, but because they are the precursors to colon cancer. If left untreated, small polyps may eventually grow larger and become cancerous. Once a cancer has formed in the colon, bleeding is a very common means of presentation. Colonoscopy is the hallmark method to detect polyps and colorectal cancers.


Each person is an individual, thus each patient’s case must be considered as such. Every person with rectal bleeding does not need a colonoscopy, just as not all bleeding is due to cancer. Rectal bleeding should be considered serious, however, until some evaluation is made. Most importantly, talk to your doctor about the nature of your rectal bleeding. Your medical history regarding the blood loss is extremely important in deciding if your problem is serious or a simple nuisance. Your age is key in this decision – general health recommendations include colonic examination for all persons over the age of 50. Thus if you are in this age group, colonoscopy will more likely be suggested to you as the proper way to determine the cause of your rectal bleeding.