What Are the Causes of Rectal Mucus?

Mucus is a slimy, slippery fluid that acts as a lubricant and protects various structures in the body. There are a number of mucus-secreting cells in the body, but mucus is most prominent in the respiratory, genital and gastrointestinal tracts, notes the University of Colorado at Boulder 1. When the gastrointestinal tract becomes infected or undergoes frequent irritation, the mucus-secreting cells may begin to produce excess mucus, which is passed through the rectum.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.

Ulcerative Colitis

Ulcerative colitis is a type of inflammatory bowel disease that is characterized by the development of ulcers, or open sores, in the lining of the colon and rectum. Ulcers develop when chronic inflammation causes weak spots in the intestinal tract. The chronic inflammation also causes the intestinal tract to produce excess mucus, which is excreted through the rectum. Other symptoms of ulcerative colitis include:

  • fatigue
  • anemia
  • weight loss
  • loss of appetite
  • rectal bleeding
  • joint pain
  • sores on the skin surface

The exact cause of ulcerative colitis is unknown, but the National Digestive Diseases Information Clearinghouse notes that it is believed to be a result of an abnormal immune system reaction to bacteria in the gastrointestinal tract 2. Treatment for ulcerative colitis differs between individuals, but general treatment options include a combination of medications or, in severe cases, surgery.


Shigellosis is a bacterial infection of the intestinal lining that is caused by a group of bacteria called Shigella 3. Shigella are spread when the bacteria is released in the stool and enters the mouth through the ingestion of contaminated food or water. MedlinePlus notes that symptoms of shigellosis may develop in one to seven days, but generally show up three days after infection 3. Shigellosis usually goes away on its own within seven days 3. Antibiotics may be given to decrease the severity of symptoms and reduce the contagiousness of the infection. It is important to drink plenty of water while symptoms persist in order to prevent dehydration.


Proctitis is an inflammation of the lining of the rectum, which is the muscular tube at the end of the colon that allows stool to exit the body. Proctitis may be caused by sexually transmitted diseases, food-borne illnesses, inflammatory bowel diseases and radiation therapy, according to MayoClinic.com 4. Treatment for proctitis depends on the cause of the inflammation. Proctitis that is caused by bacteria or infection is usually treated with antibiotics or antivirals. If proctitis is caused by inflammatory bowel diseases, medications to control inflammation or surgery may be needed.