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Mucus in the body is natural and a very important part of how the body works. Tissues produce mucus to line and protect the mouth, nose, sinuses, throat, lungs, and gut.

Most times, mucus is clear and thin. However, illness, diet, or environmental factors can sometimes increase mucus consistency. Mucus can even change in color.

People most commonly experience increased mucus when a sinus infection is present. They may notice when the mucus in a tissue after blowing their nose is a greenish color.

What happens when important mucus changes aren’t so obvious? Men and women at any age can spot signs that something is wrong based on the content of their stool as well.

Visible mucus in stool can signal a disease.Share on Pinterest
Visible mucus in stool could indicate a disease.

The mucous membrane of the large intestine helps stool to pass. A “normal” bowel movement will not produce much mucus. Yellow or clear mucus is present in such little amounts that the naked eye would not notice it.

When stool has visible mucus, it can be a sign of bacterial infections, anal fissures, a bowel obstruction, or Crohn’s disease. This type of warning sign is the body’s way of saying stop, look, and listen.

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

If the problem is obvious or persists, the next step is a call to the doctor.

Dehydration and constipation can cause mucus from the colon to leave the body. This gives the stool the appearance of increased mucus.

Increased mucus can also be a sign of illness, especially if inflammation occurs and the mucous membrane breaks down. This leaves the body more open to infection.

The complications of mucus in stool depend on the underlying cause.

Here are some possible causes of mucus in stool.

Bacterial infections

More common than other issues, bacterial infections are usually caused by bacteria such as Campylobacter, Salmonella, Shigella, and Yersinia. These bacteria are often the cause of food poisoning and other infections. Signs include:

Some cases can be quite serious, and medication from a doctor is recommended. Other cases can be treated at home and must run their course.

Anal fissures and ulcers

An anal fissure is a tear in the lining of the lower rectum. They are caused by persistent diarrhea, tough stools, and other difficult bowel situations.

An anal fissure can cause painful bowel movements, but they are not that serious. There are over-the-counter remedies to lessen pain, and most clear up within a few days to weeks.

Ulcers have similar qualities to anal fissures. If undergoing chemotherapy or radiotherapy, the body may suffer from a more severe loss of mucus called gastrointestinal mucositis.

This condition may require hospital treatment.

Bowel obstruction

More natural day-to-day symptoms like cramps, constipation, and gas or bloating can be signs of a bowel obstruction. Possible causes could be an impacted stool, hernia, tumor, or the passing of a non-food item.

Any increase in this type of activity should be reported to a doctor. If it does not clear up in a decent timeframe, hospital treatment may be necessary.

Irritable bowel syndrome, ulcerative colitis, and Crohn’s disease

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Irritable bowel syndrome can increase the amount of mucus that appears in stool.

Irritable bowel syndrome (IBS) may increase mucus production. This symptom is more common in people with diarrhea-predominant IBS than those with constipation-predominant IBS.

Ulcerative colitis, a form of inflammatory bowel disease (IBD), can result in the mucous membrane of the large intestine becoming inflamed and developing ulcers. These ulcers can bleed and may also produce pus and mucus.

Crohn’s disease is far less likely to produce increased amounts of mucus in stool. Increased mucus could be due to another issue like an anal fissure that may require a medical consultation.


Food allergies, such as those associated with nuts, lactose, or gluten, can cause mucus in the stool. Certain food items may cause discomfort and the following symptoms:

  • Bloating
  • Diarrhea
  • Rashes
  • Constipation

A doctor will help determine whether it is a food allergy or intolerance, which can often be confused. People should contact a doctor if a noticeable increase in mucus or blood in a bowel movement occurs after eating a certain food.

After a patient has discovered the changes in stool and made an appointment with a doctor, they may be asked to bring in a stool sample. This sample will be used to detect parasites, bacteria, and other illnesses.

Although many gut issues do not need lab testing, some people may be ordered to. People who have been traveling abroad are likely to be tested.

According to the Centers for Disease Control and Prevention (CDC), 30 to 70 percent of those traveling outside the United States will get a form of gut infection.

Other people who may need testing are the very young, the very old, and people with weakened immune systems. Another reason testing may occur if other symptoms like fever and dehydration are severe.

If tests come back positive for bacteria such as Campylobacter, Salmonella, or Shigella, treatment may include antibiotics, but this is not always necessary.

If the test is negative, it could be a less common bacterium such as Aeromonas, Plesiomonas, Yersinia enterocolitica, or a virus, and more tests may be ordered.

If still negative for microbes like the ones above, a doctor may ask for another stool sample to investigate further. It is possible, but rare, to have more than one microbe present at a time.

A stool sample may not be needed, however. After an initial physical exam, the doctor may request blood samples before a stool test. This whole-body approach makes it easier to detect what may be going on.

If further investigation is required, undergoing a colonoscopy, endoscopy, or even a CT may be necessary to diagnose and treat the problem correctly.

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A person can speak to a pharmacist to see if a probiotic may help with irregular bowel movements.

Bacteria found in the stool will sometimes be treated with antibiotics, and resting will help to pass and heal the symptoms.

Eating habits may need to change to lessen the chances of catching a bug again. This approach is also the case with a food allergy. Should one be present, lifestyle changes need to occur quickly.

In some instances, prescription medication and ongoing treatment will need to be taken. Such cases include Crohn’s disease and some other gut-related diseases. Surgery may be required for those with anal fissures and rectal ulcers.

Some over-the-counter probiotics and supplements can help those with irregular daily bowel movements, constipation, or diarrhea. If you want to buy probiotics, then there is an excellent selection online with thousands of customer reviews.

People should speak with a doctor or pharmacist before taking medication. Keeping a journal may help people with frequent and persistent mucus in their stool to note patterns. This tool is very helpful for doctors as well.

It is normal for a certain amount of mucus to be expelled in feces, however larger amounts can be a sign of an underlying condition.

Anyone who has recently taken a course of antibiotics or been ill may notice that levels of mucus in the stool are altered. If the levels do not return to normal within a few weeks, it is important to see a doctor.

Anyone who notices excess mucus and experiences other gastrointestinal issues should track their symptoms, how long they have been going on for, and what makes them improve or worsen. This can help a doctor create a clearer picture of what might be causing the changes.

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