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What is mucus?

Mucus is a thick, jellylike 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. As well, mucus can protect against stomach acid or other potentially harmful fluids or irritants.

The presence of mucus in stool is common. When you’re healthy, mucus is typically clear, which makes it difficult to notice. It may also appear white or yellow.

Having a noticeable increase in the mucus in your stool may be the symptom of an underlying health issue, such as:

  1. Crohn’s disease
  2. cystic fibrosis
  3. ulcerative colitis
  4. irritable bowel syndrome
  5. intestinal infection
  6. parasitic infection
  7. malabsorption issues
  8. anal fissures
  9. anal fistulas
  10. colorectal cancer (colon or rectal cancer)

Keep reading to learn what symptoms you should watch out for and when you should see your doctor.

A large amount of visible mucus in your stool isn’t normal and might be a sign of a problem. If you begin seeing mucus in your stool, the levels are probably already elevated. That doesn’t necessarily indicate you have a problem, but it’s something you should monitor.

Excess mucus in the stool is sometimes accompanied by other symptoms, which may be a sign of a bigger problem. These symptoms include:

Check out: A guide to your newborn’s poop »

Excess mucus in the stool might be a sign of a gastrointestinal (GI) problem. An intestinal mucus layer protects the rest of your body from food residue and potential pathogens in your intestines.

According to the World Journal of Gastroenterology, if an inflammatory process breaks down this mucosal layer, you might excrete mucus with your stool. This gives pathogens within your colon easier access to your body, potentially increasing your chances of becoming ill.

Although viruses such as the common cold or flu often result in increased mucus production, this typically only affects your respiratory system. It rarely results in increased mucus in the stool.

Dehydration and constipation may also produce excess mucus, or at least give the appearance of increased mucus. These changes may happen suddenly. Symptoms may resolve on their own or with medication.

Changes in mucus levels may also be the result of an inflammatory gastrointestinal condition that requires medical treatment. These conditions as well as other possible causes include:

1. Crohn’s disease

Crohn’s disease is an inflammatory bowel disease that affects your GI tract. Early symptoms may include diarrhea or fatigue.

2. Cystic fibrosis

Cystic fibrosis is a genetic disorder that results in thick, sticky mucus. This mucus often builds up in your lung, pancreas, liver, or intestines.

3. Ulcerative colitis

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

4. Irritable bowel syndrome

Irritable bowel syndrome may result in symptoms such as abdominal pain, cramping, and diarrhea, but it doesn’t cause inflammation.

Learn more: Irritable bowel syndrome vs. inflammatory bowel disease »

5. 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.

6. Parasitic infection

Parasitic infections have a variety of causes and symptoms. They can result from malaria, which is caused by infected mosquitoes, and trichomoniasis, a sexually transmitted infection.

7. 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.

8. Anal fissures

Anal fissures are small tears in your anal lining. They may be related to an inflammatory bowel disease such as Crohn’s disease or ulcerative colitis.

9. Anal fistulas

When an anal abscess or cavity heals improperly or is left untreated, you may develop an anal fistula.

10. Colon or rectal cancer

Colon or rectal cancer starts in your colon or rectum and may cause symptoms such as blood 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, finding the underlying cause may take several rounds of testing and examination.

Once your doctor has made a diagnosis, they will prescribe treatment. Lifestyle changes may resolve the issue for some. Suggestions may include:

  • Increase your fluid intake.
  • Eat foods rich in probiotics or supplements that contain probiotics, such as Bifidobacterium or Lactobacillus. Find probiotics online today.
  • Consume anti-inflammatory foods, such as low-acid and nonspicy foods.
  • Get a healthy 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.

A combination of lifestyle changes, medications, and possible surgical procedures may help relieve conditions such as anal fissures and fistulas.

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.

Keep reading: Why is my stool yellow? »

Mucus levels in your stool may change from time to time. Maintaining normal mucus production and healthy mucosal barriers throughout your body partly depends on the bacteria in your intestine.

If you’ve recently taken antibiotics or been sick, you may have noticed your stool mucus levels change. If it doesn’t return to normal within a few weeks, you should seek medical attention.

You should see a gastroenterologist, a doctor who specializes in disorders of the GI tract, if you notice excess mucus and experience other symptoms of a GI problem. Make sure to keep track of your symptoms, how long you’ve been experiencing them, and what, if anything, makes them better or worse.

It’s also important to make an effort to improve the health of your colon by eating foods rich in prebiotics and probiotics, eating colorful fruits and vegetables, and staying hydrated.

Q: When would abnormal stool be an emergency — the kind where I would need to talk to my doctor immediately or call 911?

A: First, how much stool is being produced? If you’re producing too much mucus in your stool and experience symptoms like dizziness or feeling faint, call your doctor immediately. It’s highly likely you’re significantly dehydrated, which means you may need IV fluids. If your stool is bloody or becoming black, this could indicate bleeding from your intestine or colon. If this type of bleeding happens, you may need a blood transfusion.

— Mark LaFlamme, MD

Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.