Rectal bleeding in small amounts is common and usually not life-threatening. It may present as blood in the toilet, on the outside of your stool, or with wiping after a bowel movement. Most common causes are hemorrhoids and anal fissures. However, other more serious causes include colitis (inflammation of the colon), colon polyps, diverticulosis, and cancer.
The term rectal bleeding is usually used to describe bright red blood per rectum which comes from the most distal part of the digestive tract. However, bleeding from the upper digestive tract, small bowel or proximal colon, can produce black, tarry bowel movements (known as melena), dark red bowel movements or bowel movements with blood clots.
What Causes Rectal Bleeding?
- Hemorrhoids: Hemorrhoids are swollen blood vessels in the rectum or anus that can sometimes bleed. Bright red blood typically coats the stool or blood may drip into the toilet or stain toilet paper. Bleeding can be painless if the source is internal hemorrhoids versus associated with tenderness or pain if it comes from external hemorrhoids, especially in the case of thrombosis (clotting of the blood in the hemorrhoid)
- Anal fissure: An anal fissure is a tear in the lining of the anus. Usually, this type of rectal bleeding is associated with pain often described as a sensation of tearing, ripping, or burning during or after a bowel movement.
- Diverticular bleed: Usually large volume and painless but it can lead to significant anemia (low blood count) and make the patient experience other significant symptoms related to the level of blood loss.
- Colitis: Inflammation of the colon could be from infection, lack of blood flow, medication/radiation treatment adverse effect, inflammatory bowel disease (chronic condition). This type of rectal bleeding is usually associated with diarrhea and abdominal pain. Other symptoms may be present depending on the cause of colitis.
- Colon polyps or cancer: Most people with minor rectal bleeding do not have colon cancer or another serious condition. Most colon polyps and cancers are completely asymptomatic in the early stages and the presence of rectal bleeding usually indicates large size and ulceration.
Are There Tests I Should Have?
- Rectal exam: Includes visualization of the outside of your anus and palpation (without visualization) of the inner lining of the rectum (inside the opening). It can be performed at the office.
- Anoscopy: A disposable instrument that goes a few inches into the rectum is used to see inside. It can also be performed at the office.
- Sigmoidoscopy: A flexible tube with a light and a camera is introduced into the rectum and advanced into the large intestine to visualize the lining of the intestine. It allows for biopsies (sampling of tissue) and therapeutic interventions. It does NOT require anesthesia but is limited to the lower end of the colon only.
- Colonoscopy: Similar to the sigmoidoscopy, requires insertion of a flexible tube with a light and a camera into the rectum, but this procedure includes an examination of the entire colon. It also allows for biopsies (sampling of tissue) and therapeutic interventions but it is usually performed under anesthesia.
- Imaging: In cases of significant bleeding or when the site of bleeding is not clear, a nuclear medicine test called and bleeding scan or a CT angiogram can be to detect the site of bleeding.
How Is Rectal Bleeding Treated?
The treatment of rectal bleeding depends largely on the cause. For rectal bleeding from hemorrhoids and/or anal fissures, avoidance of constipation and straining is very important. Once symptoms arise, such as pain, itching, and irritation, medications in the form of creams and suppositories (by prescription or over-the-counter) may help prevent further inflammation and bleeding. Also, physical measures such as doing sitz baths and avoiding squatting, leg press at the gym, pushing/lifting heavy weight would be very helpful.