Rectal bleeding, which is bleeding from the rectum or anus, is a scary but surprisingly common phenomenon.

Rectal bleeding is usually assumed to refer to bleeding from your lower colon or rectum, which makes up the last few inches of your large intestine. Bleeding from higher in the intestinal tract, from the stomach, duodenum, or small intestine, may also pass through the large intestine and appear to come from the rectum, notes MedlinePlus.

Causes and Risk Factors of Rectal Bleeding

The most common causes of rectal bleeding are diverticulosis, hemorrhoids, anal fissures, and colitis, according to the Cleveland Clinic.

Diverticulosis is the most common cause of rectal bleeding. It is the presence of tiny bulges, called diverticula, in the colon wall. Diverticula are common and typically do not cause problems, but can sometimes protrude through the walls of the bowels, leading to bleeding or infections.

Often called piles, hemorrhoids are swollen veins that appear at the bottom of the large intestine and outside the anus. They are caused by excessive straining, such as while making a bowel movement, sitting on the toilet too long, or, in women, pregnancy and giving birth. People who have persistent hemorrhoids are often constipated, overweight or obese, or eating a very low-fiber diet.

Hemorrhoids can be itchy, painful, and annoying, but they are rarely serious and often go away on their own. In certain cases, treatment may be needed.

Anal fissures, another cause of rectal bleeding, are tiny tears in the anus and anal canal commonly caused by straining with hard stools.

Colitis is the inflammation of the lining of the tissues of the colon. This inflammation can lead to rectal bleeding. Ischemic colitis occurs when blood flow to the colon is reduced, typically as a result of narrowed or blocked arteries. With infectious colitis, the swelling of the colon is caused by bacteria, viruses, or parasites.

Less common causes of rectal bleeding include intestinal polyps, proctitis, colon cancer, inflammatory diseases of the bowel, or rapid bleeding from the stomach or upper GI tract.

Intestinal polyps are masses of tissue that protrude from the bowel wall, sometimes causing minor bleeding. Proctitis is an inflammation of the lining of the rectum. If you have proctitis you may feel rectal pain and the continuous sensation of having to make a bowel movement.

Colon cancer is the most serious cause of rectal bleeding. Anal cancer, which is less common than colorectal cancer, can also cause rectal bleeding.

People with an inflammatory bowel disease such, as Crohn’s disease or ulcerative colitis, may also experience rectal bleeding and related symptoms, such as abdominal pain, diarrhea, constipation, ulcers, and a higher risk for colorectal cancers.

Duration of Rectal Bleeding

How long rectal bleeding lasts will vary based on the individual and condition causing it.

Rectal bleeding from hemorrhoids can last anywhere from a few seconds to several minutes with bowel movements. Bleeding may also occur occasionally between bowel movements. Talk to your doctor if you have rectal bleeding or if you have hemorrhoids that don’t clear up after a week, notes the Mayo Clinic.

4 Signs Your Hemorrhoids Warrant a Doctor's Visit

Anal fissures typically heal within a couple of weeks, according to the NHS.

Rectal bleeding associated with polyps or colorectal cancer may occur in small amounts over time until a doctor identifies the cause and treats it.

Complications of Rectal Bleeding

Light rectal bleeding or spotting due to constipation or hemorrhoids in people under 40 rarely needs medical attention. However, if your rectal bleeding is continuous or heavy, it could lead to shock, a life-threatening condition in which the body is not getting enough blood flow. If not treated, this can result in organ damage. According to the Mayo Clinic, you should seek medical attention immediately if you are experiencing rectal bleeding and any of the signs of shock, including:
  • A feeling of faintness
  • Nausea
  • Rapid, shallow breathing
  • Blurred vision
  • Dizziness or lightheadedness
  • Confusion
  • Clammy, pale skin
  • Low urine output

Untreated polyps in the colon or rectum that cause rectal bleeding can lead to colorectal cancer.

Black Americans and Rectal Bleeding

While there are no statistics on rectal bleeding and different ethnic groups, colorectal cancer disproportionately affects the Black American community. According to the ACS, Black Americans are 20 percent more likely to receive a colorectal cancer diagnosis and are 40 percent more likely to die from it than other ethnic populations.
While the reasons for this disparity are complex, they reflect racial differences in risk factors, access to healthcare, and socioeconomic status. Black Americans have higher rates of obesity, with non-Hispanic Blacks about 1.3 times more likely to be obese compared with non-Hispanic Whites, the U.S. Department of Health and Human Services Office of Minority Health reports.

Black Americans also experience greater obstacles to cancer prevention, detection, treatment, and survival. Such obstacles include lower paying jobs, lack of health insurance, lack of access to healthy and affordable foods, and low-quality housing and education.

Resources We Love

Favorite Organizations for Essential Information on Rectal Bleeding

American Society for Gastrointestinal Endoscopy (ASGE)

Founded nearly eight decades ago, ASGE is a professional organization of physicians dedicated to advancing patient care and digestive health. Get all the info you need on common causes of rectal bleeding, including hemorrhoids, anal fissures, polyps, and colon and anal cancer.

American Cancer Society (ACS)

ACS is a nationwide organization dedicated to advocating for cancer patients and eliminating cancer as a major health problem. It is the ultimate source of information if you or a loved one are worried about colorectal cancer, have recently been diagnosed, are going through treatment for colorectal cancer, or are trying to stay well post-treatment.

Cleveland Clinic

Cleveland Clinic offers an array of information on possible causes of rectal bleeding, care and treatment, and when to call a doctor.

Editorial Sources and Fact-Checking

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  12. Anal Fissures: Prevention. Cleveland Clinic. February 22, 2019.
  13. Colorectal Cancer What Should I Know About Screening? Centers for Disease Control and Prevention. February 10, 2020.
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  15. Dietary Guidelines for Alcohol. Centers for Disease Control and Prevention. December 30, 2019.
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  19. Key Statistics for Colorectal Cancer. American Cancer Society. August 31, 2020.
  20. Colorectal Cancer Rates Higher in African Americans, Rising in Younger People. American Cancer Society. September 3, 2020.
  21. Obesity and African Americans. U.S. Department of Health and Human Services Office of Minority Health. March 26, 2020.
  22. What Is Colorectal Cancer? American Cancer Society. June 29, 2020.
  23. Key Statistics for Anal Cancer. American Cancer Society. September 9, 2020.
  24. Anal Cancer Symptoms and Causes. Mayo Clinic. July 31, 2019.


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