Although there are many causes of rectal bleeding, this article will focus on 5 causes of rectal bleeding. Rectal bleeding can be frightening when it happens and in most cases, mild rectal bleeding is not a medical emergency. Profuse rectal bleeding with significant blood loss is a medical emergency and can be a symptom of a serious disease.
- Hemorrhoids Hemorrhoids are swollen veins that surround the rectum or anus. Although many people think swollen veins are abnormal, they are present in most of the population, but do not always cause bleeding. Hemorrhoids are usually caused by constipation and straining to have a bowel movement. Other factors that contribute to hemorrhoids include heavy lifting, anal intercourse and chronic diarrhea. These swollen veins are not usually life threatening and the symptoms usually resolve themselves within a few days. Internal hemorrhoids will cause small amounts of bright red blood to be visible in stool and on toilet paper. External hemorrhoids are visible and can be felt as a lump on the outside of the anus.
- Colon Cancer In colon cancer, malignant cells, called cancer cells, form in the tissues and lining of the colon. Rectal bleeding in colon cancer can appear as bright red or dark in color, depending on where the cancer is located in the colon. Cancer that is closer to the rectum will be a brighter red and cancer that is further up in the colon may appear darker. Rectal bleeding from colon cancer is generally found in the stool and not on the surface, as with hemorrhoids.
- Anal Fissure Anal fissures are small tears in the lining of the anus and are quite common. Anal fissures can be caused by constipation, anal sex and diarrhea. They are painful during and after having a bowel movement. Rectal bleeding from anal fissures will generally be bright red and comes in small amounts. Blood may be visible on toilet paper and on the surface of the stool.
- Angiodysplasia Angiodysplasia of the colon is a disease in which the blood vessels in the colon are enlarged. These enlarged blood vessels become fragile and can bleed intermittently. Rectal bleeding from angiodysplasia can be mild to severe and the color of the blood can range from bright red to dark tarry in appearance. There is generally no pain associated with this disease. Unlike anal fissures, angiodysplasia does not go away on its own and most people will need to have a surgical procedure to find the vessel that is causing the rectal bleeding.
- Ulcerative Colitis Ulcerative colitis is a chronic disease of the colon in which small ulcers form on the lining of the colon. In ulcerative colitis, there may be severe bloody diarrhea. Rectal bleeding can lead to anemia over time with this disease.