Causes of Mucus in Diarrhea

Diarrhea with mucus can be caused by a viral infection, food poisoning, or a sign of a chronic problem in your intestines.

Mucus is produced by your intestines to keep your colon lubricated, which makes it easier for stool to pass. Stool normally has small amounts of mucus, but usually you do not notice it.

Diarrhea that looks like mucus or contains a larger amount of mucus may signal an underlying inflammatory condition, such as a food intolerance, gastrointestinal infection, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), or hemorrhoids.

3. Inflammatory bowel disease

Symptoms

• Diarrhea or constipation, with stools that may have mucus or blood
• Urgency or incontinence of stool
• Abdominal cramps or discomfort

Inflammatory bowel disease (IBD) is a chronic condition that creates inflammation in the digestive tract. There are two types: ulcerative colitis and Crohn’s disease. Colitis affects the rectum and extends up through the entire colon, while Crohn’s looks like patches of inflammation throughout the colon or small intestine.

Both types of IBD can lead to frequent loose stools with mucus and blood. You may also have crampy abdominal pain, rushing to the bathroom, discomfort when having a bowel movement, and feeling like you haven’t completely emptied your bowel. If you notice these symptoms, you should see a gastroenterologist (digestive disease doctor).

Your doctor may recommend further tests or a colonoscopy to make a diagnosis. If you have IBD, you will need to start medications to help decrease the inflammation in your colon. Some patients may need surgery if their disease is severe.

4. Food intolerance

Symptoms

• Diarrhea, which may be streaked with mucus
• Abdominal pain or discomfort
• Gas or bloating

Food intolerances can lead to increased mucus in stool.

Some people may find certain foods cause abdominal discomfort and diarrhea. A common one is lactose intolerance, which is a reaction to lactose that’s found in dairy foods and drinks. Others include intolerance to gluten or spicy food. Treatment is to avoid these dietary triggers.

Keep track of what you’re eating in a food diary and bring it to your doctor who can help identify what is causing the symptoms. Trying an elimination diet where you stop eating trigger food groups may improve your symptoms.

An allergy doctor can help to pinpoint your allergies and intolerances through a skin test or blood test. Seeing a nutritionist can also help you create a diet plan that avoids your dietary triggers.

5. Hemorrhoids

Symptoms

• Blood on toilet paper or blood or mucus in stool
• Rectal pain
• Itching in the anal area

Hemorrhoids are swollen veins in the rectum. You may feel or see some hemorrhoids outside the rectum (external hemorrhoids), while others are inside (internal hemorrhoids).

They are common and can cause bleeding, itching or pain. There can also be mucus in the stool or toilet paper.

Hemorrhoids can be caused by hard stools or straining when going to the bathroom. They often improve with over-the-counter medications, such as stool softeners, fiber, or topical creams (like Preparation H or witch hazel). Daily sitz baths are also helpful.

If your symptoms do not improve or you notice a lot of blood in your stool, see your doctor. If the hemorrhoids are severe, your doctor may recommend a colonoscopy or procedure to remove them.

Other possible causes

A number of conditions may also cause mucus in diarrhea.

Inflammatory

• Infectious: Bacterial, viral, and parasitic infections can cause diarrhea that looks like mucus. They can directly infect the cells of the digestive tract and cause irritation that causes diarrhea. Common foreign invaders include rotavirus, norovirus, E. coli, salmonella, and giardia. When traveling in developing countries, diarrhea caused by bacteria and parasites is often called traveler's diarrhea.
• Genetic: Many genetic conditions, such as cystic fibrosis, can cause chronic irritation that leads to diarrhea.
• Autoimmune: Conditions with an autoimmune component can also cause diarrhea with mucus. This includes celiac disease, which is an immune reaction to gluten.

Environmental

Environmental causes can be related to certain exposures or lifestyle habits.

• Diet: Not only can viruses and bacteria infect the digestive tract through contaminated food and drink, but a specific diet can also contribute to diarrhea that looks like mucus. Allergies to foods such as cow’s milk, soy, cereal grains, eggs, and seafood may cause chronic diarrhea.
• Medications: Many medications have diarrhea as a side effect. For example, antibiotics destroy both good and bad bacteria and disturb the natural balance of bacteria in the intestines. That can lead to diarrhea with mucus or another infection, like C. Difficile colitis. Many other drugs that also destroy or distress the intestines, such as cancer drugs, can also cause diarrhea.