Many patients often report traces of blood in their faeces, which is medically known as rectal bleeding. This is a cause for concern, especially if it is a chronic issue or if it takes place with alarming severity. 

Even if only minor traces of blood are detected or there is no pain involved, receiving treatment for this condition is important for an individual’s overall digestive health. One of the most common questions gastroenterologists are asked when it comes to rectal bleeding is usually related to what causes it.

This post looks into this all-important question. 


A leading cause of rectal bleeding, haemorrhoids are swollen veins in the rectum, which are internal in nature, or in the anus, which are external.

Also known as piles, haemorrhoids often develop due to constipation or any strain caused when passing stools, pregnancy, lifting heavy objects on a frequent basis, obesity, or anal intercourse.

There are numerous ways to treat this condition, although treatments usually focus on addressing constipation, straining habits, or even changing work habits if necessary. In certain cases, surgery may even be necessary.

Anal fissures

Another common cause of rectal bleeding is anal fissures, which are splits or tears in the lining of the anus. These cause bleeding and burning pain, especially after bowel movements.

Usually caused when a hard stool is passed, the pain is the result of a spasm in the sphincter muscle. While fissures may be mistaken for haemorrhoids, fissures have the ability to heal themselves if they aren’t severe. If this isn’t the case, ointments can be applied or medication can be taken to relieve pain.

If fissures keep occurring, however, surgery may be needed to rectify the issue.


Diverticulosis is what happens when small pouches, which are known as diverticula, form in weakened sections in the intestine lining and extend out through the bowel wall.

Diverticula are more likely to be found among older generations and can be diagnosed through a colonoscopy or a sigmoidoscopy. While Diverticulosis is not particularly threatening, it can lead to rectal bleeding and infection if left untreated.

Inflammatory bowel disease

Inflammatory bowel disease (IBD) is what takes place when there is inflammation of the small or large intestine. There are two primary types of IBD, Crohn’s disease and colitis, both of which are characterised by inflammation within the digestive system. Rectal bleeding is a symptom of IBD.


Ulcers refer to the sores that occur in the stomach lining or in the first part of the small intestine. Usually caused by an imbalance of digestive fluids, stomach aches, black stool, and rectal bleeding are some of the most common symptoms of this condition.

Usually treated without surgery, treatment for ulcers include specialised diets, antibiotics, and medication that neutralises gastric acid and those that increase gastric acid resistance within the digestive system.

Oversized polyps

Another condition that can cause rectal bleeding is the presence of big polyps. Unlike some of the conditions outlined above, polyps need to be diagnosed and treated as soon as possible. 

If left untreated, polyps can lead to colorectal cancer because they’re precancerous. Given that this type of cancer can be treated effectively if detected early enough, it’s important to get medical attention if blood can be seen among stools. For those with a history of colorectal cancer extra vigilance is required.

To treat polyps, a colonoscopy is often required to locate and remove these growths.

Anal fistula

A fistula refers, medically, to an abnormal channel, tunnel, or passage connecting one internal organ to another or to the outside surface of the body. For those experiencing rectal bleeding, an anal fistula is a common culprit.

This is generally the result of an infection in the perianal area and surgery is usually required in order to sever this connection. The causes of the fistula, itself, vary and could be the result of Inflammatory Bowel Disease, tuberculosis, surgery, or radiation.

Seek treatment for rectal bleeding

Rectal bleeding could be a sign or symptom of a number of different gastroenterological conditions. Whatever the cause is, it’s important to seek immediate diagnosis and treatment in order to prevent more serious conditions from emerging.

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