Mucus is a thick, jelly-like substance. Your body primarily uses mucus to protect and lubricate your delicate tissues and organs.

It’s also used to reduce damage that may be caused by bacteria, viruses, or fungi. Mucus can also protect against stomach acid or other potentially harmful fluids or irritants.

The presence of mucus in stools can be common. When you’re generally healthy, mucus is typically clear and appears in such small amounts that it’s often difficult to notice.

But if you start to see a noticeable increase in mucus in your stools, it may be the symptom of an underlying health issue.

Two common causes of mucus in your stool are dehydration and constipation. These two conditions may cause the normal mucus in your colon to leave the body. Mucus caused by these issues may resolve on its own or with medication.

Changes in mucus levels may also be the result of an inflammatory gastrointestinal condition that requires medical treatment. Some of these conditions include:

Crohn’s disease

Crohn’s disease is an inflammatory bowel disease that affects your gastrointestinal (GI) tract. Early symptoms may include diarrhea or fatigue, as well as an excess of mucus in the stool (due to a disrupted mucus barrier in the inflamed intestines).

Cystic fibrosis

Cystic fibrosis is a genetic disorder that results in the buildup of thick, sticky mucus in your lungs, pancreas, liver, or intestines. Cystic fibrosis may also cause mucus in the stool.

Ulcerative colitis

Like Crohn’s disease, ulcerative colitis is an inflammatory bowel disease. It’s a chronic condition that causes inflammation in your large intestine or rectum.

An increase in mucus secretion often occurs when the body is dealing with the symptoms of ulcerative colitis, which in turn can increase the mucus in your stools.

Irritable bowel syndrome

Irritable bowel syndrome (IBS) is the name for a group of symptoms such as abdominal pain, cramping, and altered bowel habits that occur outside of a disease diagnosis.

Currently, research suggests that mucus in the stool may be connected to the diarrhea someone experiences as a symptom of their IBS.

Intestinal infection

Intestinal infection can also lead to mucus in the stool. Examples include infection from bacteria such as salmonella and shigellosis, which can occur from eating contaminated food.

Researchers think bacteria may stimulate mucus production, causing mucusy stools. Severe diarrhea can also increase mucus in stools.

Malabsorption issues

Malabsorption issues occur when your bowel is unable to properly absorb certain nutrients. Conditions related to malabsorption include lactose intolerance and celiac disease.

Colon or rectal cancer

Colon or rectal cancer starts in your colon or rectum and may cause symptoms such as blood in your stool, mucus in your stool, rectal bleeding, and unexplained weight loss.

There’s no one-size-fits-all treatment for abnormal mucus in the stool. To treat the excess mucus, your doctor will need to diagnose and treat any underlying problems, which may be related to inflammation in your colon.

Most doctors will begin with a physical exam and a blood test. The test results will give your doctor an understanding of your basic physical health.

If additional information is needed, your doctor may request more tests. These may include:

For some people, a diagnosis may be reached quickly. For others, the underlying cause may not be determined despite extensive testing.

Because mucus in the stool may be a symptom of an underlying condition, your treatment will vary depending on your diagnosis.

For some mild cases, especially those connected to periodic dehydration or constipation, lifestyle changes may help resolve the issue. Suggestions may include:

  • increasing your fluid intake
  • eating foods rich in probiotics or supplements that contain probiotics, such as Bifidobacterium or Lactobacillus
  • establishing a nutritious balance of fiber, carbohydrates, and fat in your diet

Prescription medications and ongoing treatment may be necessary for people with chronic conditions, such as Crohn’s disease, cystic fibrosis, ulcerative colitis, and irritable bowel syndrome.

If your doctor discovers cancer, you may be referred to an oncologist. This is a specialist who’ll treat your cancer, and this treatment may reduce and ease the symptoms you’re experiencing.

While occasionally seeing a bit of mucus in your stool is typically nothing to worry about, if it’s accompanied by these other symptoms, you should see a doctor ASAP:

  • persistent diarrhea
  • stomach cramping
  • blood in stool
  • fatigue
  • nausea
  • vomiting
  • unexplained weight loss

Even if there aren’t any other symptoms, persistently seeing mucus in your stool could be a sign of a more serious health issue, and it’s a good idea to see a doctor.

Most people have mucus in their stools — it’s just typically such a small amount that it isn’t noticed.

Noticeable mucus could be a symptom of a more benign issue, such as occasional dehydration or constipation, or it could be a more chronic health issue.

Depending on the co-occurring symptoms you experience, as well as the duration and amount of mucus in your stool, you may want to talk with your doctor to rule out something more serious.

Your doctor will ask you about your medical and dietary history, do a physical exam, and may run some tests — including blood tests and stool sample tests — if they believe there could be an underlying condition.