Rectal Discharge (Blood, Mucus, Feces) Causes and Types

A discharge may be the release of any secretion from any surface of the body or the cavities. Sometimes these discharges may arise from much deeper in the body. Different types of discharge may occur for different reasons. When it comes to the rectum, stool is technically not considered as an abnormal discharge as it  is the waste material in the bowels that is normally expelled several times a day or every few days. Similarly flatus (gas) is not considered an abnormal rectal discharge.

What is a rectal discharge?

A rectal discharge in this context is any abnormal solid or fluid that is expelled from the rectum through the anus, except for stool and flatus. Sometimes the stool can be very soft and runny or even entirely watery, but this as well is not considered as abnormal rectal discharge although it is abnormal stool. Rectal discharge is often mucus, pus or blood and there are different reasons why this occurs.

diarrhea toilet

Meaning and Types

The reasons why the different rectal discharges occur:

  • Blood is usually indicative of a break in a blood vessel lining the bowels. This is often related to tears in the mucosal lining of the bowels as is seen with ulcers (open sores).
  • Pus is usually due to an infection and is composed of dead cells, microbes like bacteria, breakdown products of cells and even blood as well tissue fluid. It may be released from a burst abscess in the bowel walls.
  • Mucus is a sticky discharge produced by the mucus-producing cells lining the gut and certain glands that empty its secretions into the gut. It is normally present in the bowels and stool but should not be excessive.
  • Anal leakage is small amounts of very watery stool that seeps out of the anus even without defecating. This is due to conditions like fecal impaction and bowel incontinence.

Many of these discharges like blood, pus or mucus are not noticed in small volumes especially when mixed with stool. The source of the mucus and blood is not necessarily near or from the rectum. Sometimes it can originate higher up in the digestive tract. Discharges from higher up the gut like the esophagus, stomach or first parts of the small intestine may eventually be passed out through the rectum.

However, these discharges from the upper gastrointestinal tract may also not be noticed as it is digested, degraded or even absorbed during its transit to the rectum. Black, tarry stools are medically referred as melena and is more likely due to bleeding from higher up the gut. Mucus from high up in th gut rarely reaches the rectum without being digested or mixing extensively with the gastrointestinal content to the point that it is masked in the stool.

Rectal Dischage

Causes of Rectal Discharge

There are a number of different causes of rectal discharge. It is usually associated with inflammation and injury to the bowels. Small volume mucus and blood discharge may not be considered a medical emergency. However, large volume bloody diarrhea needs immediate medical attention or it can lead to serious and even fatal complications within days and sometimes even within hours.


Hemorrhoids is one of the more common causes of both a mucus and blood discharge from the rectum. It s usually noticed when wiping after a bowel movement. In hemorrhoids, the rectal veins are swollen and tortuous. Acute episodes of inflammation often make bowel movements and wiping painful with a burning during and after defecation. Diarrhea and constipation can exacerbate pre-existing hemorrhoids.

Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is another common cause of bloody and mucoid discharge from the rectum. Inflammation of the bowels along with ulcers that form in the bowel walls contribute to both the blood and mucus that is seen in the stool. IBD is an autoimmune condition of which there are two types – Crohn’s disease which can affect any part of the gut and ulcerative colitis which mainly occurs in the lower bowels.

Irritable Bowel Syndrome

Another common cause of mucus discharge is irritable bowel syndrome (IBS). It is a disturbance of normal bowel physiology that presents as abdominal pain, diarrhea, constipation or both diarrhea and constipation. There is usually no blood discharge due to the IBS although hemorrhoids is more likely to occur with the altered bowel habit. It is therefore bleeding hemorrhoids that may cause a bloody rectal discharge, and not the IBS itself.

Anal Fissure

Anal fissures are tiny tears in the delicate lining of the anus. It is usually caused by diarrhea or constipation but may also be associated with infections of the anus, inflammatory bowel disease or anal cancer. Fissures present with pain, itching, burning and bloody discharge, similar to hemorrhoids. Bleeding is often noticed after a bowel movement when wiping.


Proctitis is an inflammation of the rectum that occurs with a number of bowel conditions, such as inflammatory bowel disease (IBD), infections especially sexually transmitted infections (STIs), radiation therapy to the pelvic region, antibiotic use and a host of other causes of diarrhea. Mucus and bloody discharge are usually present, along with rectal pain, constant urging to pass stool and a feeling of fullness in the rectum.

Fecal Incontinence

Fecal incontinence means that stool is not able to be restrained and may pass out of the anus involuntarily. It can be small volumes or sometimes the entire emptying of the rectum. In acute cases, fecal incontinence is often due to diarrhea and constipation but chronic cases is usually due to muscle and/or nerve dysfunction that prevents the anus from preventing the leakage of the rectal contents.


Gastroenteritis is a common reason for acute diarrhea. It is usually due to infections, either caused by bacteria, viruses or protozoa. Viral gastroenteritis is a frequent cause of acute diarrheal outbreaks commonly referred to as the stomach flu. Mucus discharge is seen mainly with severe bowel inflammation. Sometimes there may even be bloody diarrhea as tiny blood vessels in the bowel wall ruptures due to the extensive inflammation.

Food Intolerance

Food intolerances are conditions where the digestive system cannot process certain foods. It is often due to the body’s inability to digest specific foods as a result of abnormalities with the enzymes that are needed to break down these nutrients. Lactose intolerance is a common type of food intolerance due to deficiency of the enzyme lactase. It leads to diarrhea and a mucus discharge may be seen especially with the stool.


  1. Rectal Discharge. Health Grades

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