Small amounts of mucus in the stool is normal. However larger amounts of mucus in their stool, may indicate irritable bowel disease (IBD) or other medical conditions.

Research from 2020 states that mucus and mucus barriers in the gut are crucial in maintaining a person’s gut health. The mucus can defend against bacteria, digestive enzymes and acids, and other toxins to maintain a stable environment in the gut.

It also acts as a natural lubricant and helps stool to pass.

However, problems with the mucus barrier can result in intestinal inflammation and contribute to the development of IBD. A main symptom of IBD is mucus in the stool.

This article discusses if it is normal for mucus to appear in the stool and possible causes. It also looks at when to contact a doctor and potential treatment options.

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The mucous membrane of the large intestine helps stool to pass. According to research from 2019, it is normal for a small amount of mucus to be present in stool.

A typical bowel movement will not produce much mucus. It may be tawny or clear in color, and a person is unlikely to notice it.

When stool has visible mucus, it can be a sign of other health conditions, such as irritable bowel syndrome (IBS), ulcerative colitis (UC), or Crohn’s disease.

Other signs to look for:

  • increased amounts of mucus
  • blood or pus in the stool
  • stomach pain, cramping, or bloating
  • sudden changes in stool frequency, consistency, or color

A person should contact a doctor if they notice mucus in their stool.

Here are some possible causes of mucus in stool.

Crohn’s disease

Crohn’s disease is a long-term condition that causes inflammation in the digestive tract, which runs from the mouth to the anus. It is a form of IBD.

In people with Crohn’s, the layer of mucus in the digestive tract is thicker, so the body secretes excess mucus in the stool. However, during severe flare-ups, the body produces less mucus, which may mean less mucus in the stool.

Other symptoms of Crohn’s includes:

  • persistent diarrhea
  • rectal bleeding
  • abdominal cramps
  • abdominal pain
  • constipation
  • urgent need to have a bowel movement
  • the feeling of an incomplete bowel evacuation

Ulcerative colitis (UC)

UC is another form of IBD. It occurs due to an overactive reaction of the immune system. It can flare-up, or be active, at times and be inactive at other times.

During a flare-up, the mucous membrane of the large intestine becomes inflamed and develops ulcers. These ulcers can bleed and produce pus and mucus. Mucus in the stool is more likely during a flare-up.

Other symptoms of UC include:

  • urgent and loose bowel movements
  • blood in the stool
  • abdominal cramps and pain
  • persistent diarrhea

Irritable bowel syndrome (IBS)

People living with IBS may notice whitish mucus in their stool.

Other common symptoms of IBS include abdominal pain and changes in bowel movements, such as constipation and diarrhea.

People with diarrhea-predominant IBS are more likely to have mucus in their stool than people with constipation-predominant IBS.

Other symptoms of IBS include bloating and the sensation that a person has not finished the bowel movement.


Proctitis is inflammation of the lining of the rectum that can be short-term or long-lasting. The most common symptom is having a frequent and urgent need to have a bowel movement.

Another symptom of proctitis is having discharge of mucus or pus from the rectum, which a person should report to a doctor right away.

Other symptoms include:

  • a feeling of fullness in the rectum
  • rectal pain
  • abdominal cramping
  • pain during bowel movements
  • rectal bleeding
  • diarrhea
  • constipation
  • swollen lymph nodes in the groin

Intestinal infection

Infection in the gastrointestinal (GI) tract might also cause mucus in the stool. Infections can occur as a result of a bacteria, virus, or parasite.

Some parasitic infections may lead to bloody diarrhea with mucus.

Other symptoms include:

Learn more about gastrointestinal infections here.

Colorectal cancer

Colorectal cancer refers to cancer of the colon or rectum, which are part of the digestive tract.

Colon cancer begins in the mucosa, the inner layer of the bowel wall, which contains mucus-producing cells called goblet cells. People with colon cancer might see mucus streaked with blood in their stools.

Other symptoms include:

  • change in bowel habits that lasts for more than a few days
  • a feeling that a bowel movement is needed but the person is not relieved after having one
  • dark brown or black stool as a result of blood
  • bright red blood in the stool
  • cramping in the abdomen
  • weakness
  • fatigue
  • weight loss

Mucus in the stool may have other causes.

These include:

  • celiac disease, otherwise known as gluten intolerance
  • other food intolerance, including lactose, sucrose, and fructose intolerance
  • lack of dietary fiber, which is needed to bulk out stool and help move waste smoothly out of the body
  • intestinal parasites, such as tapeworms, hookworms, and pinworms
  • cystic fibrosis, a genetic disorder that causes an excess of mucus in the intestines and other organs

Usually, the first step towards understanding what is causing mucus in the stool is to test a stool sample.

A healthcare professional will give instructions on how to take a sample. It usually involves collecting a sample of stool in a clean container and, if a person is unable to hand it in immediately, storing it in the fridge to prevent bacteria from building up.

Once a healthcare professional has the sample, they can test it for bacteria and other substances from the digestive system.

Depending on the stool sample results, a person may need further tests to investigate the cause of excess mucus in the stool. Tests include:

  • blood tests
  • endoscopy, which involves inserting a thin, flexible tube with a camera and light on the end, through the mouth or into the rectum
  • colonoscopy, which is a type of endoscopy that examines the lower part of the digestive tract
  • imaging tests, such as CT scan, ultrasound, and MRI scan

It is normal for a small amount of mucus to be present in stool. If a person regularly notices excess mucus or other changes in bowel movements accompanying it, they should talk with a doctor.

If mucus in the stool happens alongside other symptoms, it could be a sign of a condition that requires investigation and treatment.

A person should contact a doctor if they experience:

  • persistent diarrhea
  • abdominal pain
  • blood in the stool
  • vomiting
  • unexplained fatigue
  • unexplained weight loss

To help a doctor diagnose the issue, a person should keep a record of their bowel movements and any other symptoms. Keeping a food journal might also help identify food-related conditions.

Treatment will depend on the results of diagnostic tests.

If mucus in the stool is related to diet, a doctor might recommend drinking more water, increasing fiber intake, or taking probiotics.

Treatment might include prescription medication and lifestyle changes for long-term conditions such as Crohn’s, UC, and IBS.

If doctors diagnose cancer, they will refer a person to an oncologist, a specialist cancer doctor, who will devise a treatment plan specifically for them.

Having a small amount of mucus in the stool is normal.

Excess mucus can occur due to IBS, Crohn’s, UC, or proctitis. It may also be an indication of colon cancer.

If a person is concerned about the amount of mucus in their stool or experiences other symptoms, they should talk with a doctor.

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