Mucus in stool is relatively common and can be caused by constipation or dehydration. However, in some cases, it points to a more serious underlying condition.

Mucus is a thick, jelly-like substance. Your body primarily uses mucus to protect and lubricate your delicate tissues and organs. It can help reduce the damage caused by bacteria, viruses, or fungi and protect against stomach acid or other potentially harmful fluids or irritants.

When you’re generally healthy, mucus is typically clear and appears in such small amounts that it’s often difficult to notice. Dehydration and constipation can cause the typical mucus in your colon to leave the body.

But while a small amount of mucus in your stool is common, if you see a lot of it, if it changes color, or if it looks bloody, you may have an underlying condition that needs treatment. Read on to learn about more possible causes of mucus in stool.

Hemorrhoids are swollen veins located around the anus or in the lower rectum. They can be either internal or external. On the other hand, rectal prolapse is when your rectum starts to push through the anus.

Both hemorrhoids and rectal prolapse can lead to a small amount of mucus leaking into the stool. This is called rectal discharge.

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

IBS is different than IBD. It’s not an inflammatory condition, and it refers to a dysfunction in the bowel whose cause is generally unknown.

That said, IBS is another condition that can cause mucus in stool and symptoms such as stomach pain, diarrhea, and nausea.

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. Parasitic infections can also lead to mucus in stool.

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

There are also conditions that can prevent you from absorbing fats, which are then excreted in your stool. This is called steatorrhea and can be caused by conditions like pancreatitis and gallstones.

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.

Although less serious causes often cause these symptoms, if you experience this, see your doctor for an evaluation.

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 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.

Your treatment depends 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

In addition, 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.

While hemorrhoids can cause bloody stool, if you’re seeing a lot of blood or your stool is turning black, this could indicate bleeding from your intestine or colon. If this type of bleeding happens, you may need a blood transfusion.

But 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.

What color is IBS mucus?

Stool mucus caused by IBS tends to be white or yellow.

What food causes jelly-like mucus in the stool?

Foods that may contribute to mucus in stool, particularly if you have an inflammatory condition, include high fat, low protein, and low fiber foods, as well as foods containing certain additives.

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.