Healthy Living

Mucus in Your Stool: Is It Bad?

Mucus in Stool: 12 Likely Reasons For Slimy Mucus in Your Poop

Functions of Mucus

Mucus is a very important substance in the body. Tissues produce mucus to protect the linings of the mouth, throat, sinuses, nose, lungs, and gut. The functions of mucus are:

  • Lubrication - The lining of the digestive and respiratory system are moistened and lubricated by mucus to prevent them from drying as well as reducing friction. Digestion is a complex process, and for our intestinal engines, mucus serves as the oil. 
  • Protection - In our body, mucus serves as a protective fluid. The delicate cells that line our stomach and intestines are protected by mucus. The protective role of mucus in the stomach during the process of digestion is a classic example. Hydrochloric acid is released by specialized cells in the stomach. The stomach has to protect itself from its own acid through a thick mucus barrier secreted by the stomach wall. When this mucus barrier is inadequate, stomach ulcers are formed.
  • Defense - Mucus also protects the body from invading organisms since it contains enzymes, proteins, and antibodies that help mucus fight off infections.

Mucus in Stool

Stool is passed with the help of the mucous membrane of the large intestine. Much mucus is not produced during normal bowel movements. In stools, yellow or clear mucus may be present in little amounts, so they cannot be easily seen with the naked eye. If visible amounts of mucus are present in the stool, it may indicate bacterial infection, anal fissures, Crohn's disease, or bowel obstruction. It is the body's way of telling that something is wrong. 

A person can even look for other abnormal signs and symptoms, such as an increased amount of mucus in the stool, the presence of blood or pus in the stool, cramps, bloating, stomach pain, sudden changes in bowel movements, and changes in the stool's consistency and color. If you continue to experience these signs and symptoms, consult a doctor right away. 

Mucus from the colon can leave the body if the person is dehydrated or constipated. An increased amount of mucus can also indicate illness, particularly if the mucous membrane breaks down and inflammation occurs, making the body become more susceptible to infection.

It is considered normal when small amounts of mucus are present in the stool since the digestive tract is constantly producing mucus. Thus, if there is a small amount of mucus in the stool, then it should not be a cause for concern. Rather than a distinct medical condition, mucus in the stool is considered as a sign or symptom.

There are other symptoms that accompany the presence of mucus in the stool. Symptoms may include bloating, abdominal pain, and pus in the stool. Seek medical help if you have any of the following signs and symptoms:

  • Presence of blood or mucus in the stool
  • Passing pink-colored mucus
  • Passing coffee-colored mucus with visible blood clots
  • Abdominal pain
  • Bloating or abdominal cramps
  • Diarrhea
  • Changes in bowel movements
  • Changes in the stool's consistency 

When the lining of the digestive tract is damaged or inflamed, it often results in blood in mucus. If the mucus is pinkish or reddish in color, it could indicate bleeding from the inside of the large intestine. If the mucus is dark or brownish in color, it could indicate bleeding in the small intestine, stomach, or esophagus.

Mucus in the stool is abnormal when there is an excessive amount of it or when mucus has an unusual color. When a person experiences abdominal cramps, discomfort, changes in bowel movements, rectal bleeding, bloating, or fever, along with passing mucus in stools, it may indicate any of the following conditions:

1. Infection

Diarrhea, nausea, and vomiting are caused by infections due to viruses, bacteria, or parasites. A gastrointestinal infection also causes excessive mucus production.

  • Viral gastroenteritis - It is usually caused by astrovirus, rotavirus, and norovirus.
  • Bacterial gastroenteritis - It occurs when a person consumes raw meat or contaminated food or water.
  • Shigellosis - It is an intestinal infection caused by a group of bacteria called Shigella. When contaminated food or water is consumed, bacteria in the intestinal walls develop. People who live in overcrowded areas are more susceptible to this infectious disease. The symptoms of the infection are bloody diarrhea, vomiting, and nausea, which can lead to dehydration. Sometimes, the infection resolves on its own after a few days, but to relieve discomfort, antibiotics may be administered.

2. Proctitis

In this condition, the lining of the rectum is inflamed. The rectum, where the stool passes out of the body, is situated at the end of the colon. Proctitis can be due to sexually transmitted diseases, radiation therapy, infection, or inflammatory bowel disease. This condition causes the following symptoms:

  • Diarrhea
  • Abdominal pain
  • Rectal bleeding and swelling
  • Frequent urge to have bowel movements

This condition is usually treated with a course of antibiotics. However, in some cases, surgery may be required if the condition is due to chronic inflammatory bowel disease. 

The most common bacteria that can cause bacterial gastroenteritis and food poisoning are Campylobacter, Shigella, Salmonella, and Yersinia. Their common signs and symptoms are diarrhea, nausea, fever, cramping, and vomiting. Some people can have severe symptoms, which need immediate medical care and treatment, while some only have mild symptoms, which can be treated at home. 

3. Anal Fissures 

An anal fissure is a tear in the lining of the lower rectum. It is usually caused by passing hard stools (constipation) and persistent diarrhea. Although an anal fissure is not always serious, bowel movements can be painful. To reduce the pain, over-the-counter medications can be taken. Usually, the condition resolves on its own within a few days to a few weeks.

4. Bowel Obstruction

The common signs of a bowel obstruction are cramps, gas or bloating, and constipation. The possible causes of a bowel obstruction are tumors, hernia, impacted stool, or passing of a nonfood item. Hospital treatment may be required if the symptoms persist or when the condition does not clear up within the expected time frame. 

5. Irritable Bowel Syndrome (IBS) and Crohn’s Disease

Mucus production may increase due to irritable bowel syndrome (IBS). An increased production of mucus is more commonly observed in people who have diarrhea-predominant IBS than those who have constipation-predominant IBS. It is unlikely for people with Crohn's disease to produce excessive mucus in their stool. An increased production of mucus may be due to other issues, such as an anal fissure, which may need medical consultation.

6. Cystic Fibrosis

Cystic fibrosis is a genetic disorder. In this condition, the mucus production in the body is affected, wherein there is a thick buildup of mucus in the lungs and the digestive system. 

7. Malabsorption

When the bowels are unable to properly absorb the nutrients that the body needs, malabsorption issues occur. Such conditions include celiac disease and lactose intolerance. 

8. Anal Abscess and Anal Fistulas

When an anal cavity or abscess is left untreated or when it is not completely healed, an anal fistula may develop and causes leakage of mucus in the stool.  

9. Rectal or Colon Cancer

Rectal or colon cancer starts in the rectum or colon, and usually cause symptoms, such as rectal bleeding, blood in stool, and unexplained weight loss.

10. Hemorrhoids

Mucus in the stool can also be due to the presence of internal hemorrhoids. The other common symptoms associated with hemorrhoids are constipation, anal itching, and the presence of blood in the stool.

11. Food Allergies

Mucus in the stool may be excreted when the person is allergic to nut, gluten, or lactose. Other symptoms may also be experienced, such as skin rash, diarrhea, constipation, and bloating.

12. Diverticulitis

In this condition, the large intestine develops a pouch, which leads to the production of mucus and its presence in the stool. 

When to See a Doctor

Consult a doctor immediately if you have any of the following symptoms:

  • Excessive mucus in the stool
  • Regularly passing stools with visible mucus
  • Changes in the color or consistency of stools
  • Frequent bowel movements or diarrhea
  • Bloody stools
  • Vomiting
  • Abdominal pain


The amount of mucus in the stool may vary. Most of the time, the normal production of mucus all over the body somewhat depends on the intestinal bacteria. The amount of mucus in the stool may significantly change when you have recently taken antibiotics or when you have an illness. 

You can consult a gastroenterologist, a doctor who specializes in gastrointestinal disorders if you continue to experience gastrointestinal problems. It is also important to keep your colon healthy by staying well-hydrated, consuming prebiotic and probiotic foods, and incorporating fresh fruits and vegetables into your daily diet.