You may think of mucus as the slimy stuff you cough up when you're sick. But it can also show up at the other end: in your poop.
Many parts of your body make mucus, including your intestines. It lines your digestive tract, creating a protective layer against bacteria. It also helps waste pass smoothly through your colon. Some of it can stick to poop as it leaves your body.
Causes of Mucus in Stool
Different digestive problems can make more mucus show up in your stool. Some are serious and long-lasting. Others can clear up quickly. Problems that can cause mucus include:
Irritable bowel syndrome (IBS)
About half of people whose IBS causes diarrhea report that they have mucus in their stool. That mucus may be whitish. Some research suggests that you may be more likely to have mucus with IBS if you also are depressed or have anxiety.
Crohn’s disease
This inflammatory bowel disease (IBD) causes your digestive tract to swell and become irritated. Diarrhea and rectal bleeding are common symptoms. When the disease is active, you might see blood or mucus in your stool. Bloody diarrhea, often accompanied by mucus or pus, signals that it’s time to call your doctor. One possible cause: a fistula, or an abnormal opening, around your rectum or anus through which mucus, pus, or stool can drain.
Ulcerative colitis (UC)
This type of IBD causes sores in the intestines. They can bleed and make pus and mucus, which you might see when you go to the bathroom. This is more likely to happen when your UC flares, or becomes active. UC also often causes diarrhea, belly pain, and cramping.
Proctitis
This is inflammation of the lower part of your large intestine, called the rectum. Sexually transmitted infections like gonorrhea and chlamydia, foodborne illnesses like salmonella, radiation therapy, and IBD can cause proctitis, leading to blood or mucus in your poop as well as other symptoms, such as pain around your rectum, anus, or the left side of your abdomen.
C. difficile (C. diff )
Infection with this type of bacteria can cause severe diarrhea that may lead to dangerous dehydration and electrolyte imbalances that put you at risk of low blood pressure, low blood volume, and kidney failure. Severe infection can cause life-threatening damage to the lining of your intestines. When you have C. diff, your poop may smell very bad and will occasionally have mucus.
Food poisoning
Certain types of food poisoning, such as salmonella and shigella, can cause diarrhea that contains mucus or blood, along with other unpleasant symptoms, like stomach cramps, fever, and vomiting.
Bacterial infections
These infections, which include C. diff, shigella, and salmonella mentioned above, can lead to stool that contains mucus. Other bacterial infections that also can cause mucus in your poop include campylobacter, which you can get from eating undercooked poultry and drinking raw milk or contaminated water, as well as Yersinia enterocolitica, caused by eating or handling undercooked pork.
Parasitic infections
Parasites, which are tiny, sometimes worm-like organisms, can cause infections in your intestinal tract. The two main types of parasite that can infect your digestive system are called protozoa and helminths. Parasites can cause dysentery, a disease that causes severe diarrhea that contains blood or mucus, as well as nausea, vomiting, fever, cramps, and weight loss.
Colorectal cancer
The most common type of colorectal cancer, adenocarcinoma, starts in the mucosa, which contains cells that make mucus. That mucus keeps your rectum and colon lubricated. Polyps, or growths, can develop on the mucosa, and these growths can become cancerous. If you have excess mucus in your poop, it’s probably due to something other than polyps, but you should not hesitate to talk to your doctor. Additional potential signs of polyps -- and cancer -- include blood in your poop and other lasting changes to your bowel habits. Keep in mind, though, that colorectal cancer does not always have symptoms at all. Ask your doctor about when you should be screened for this disease.
Anal fistulas or rectal ulcers
Anal fistulas are infected tunnels between the skin and the anus. They can form after an abscess. They are a potential complication of IBD, and they also can be caused by anal sexually transmitted diseases, injury, tuberculosis, and radiation therapy around your pelvis. They can sometimes cause mucus, as well as pus and blood, to drain from the anal area. Rectal ulcers, caused by injury to the lining of your rectum, are open sores inside your rectum that can also cause mucus or blood to appear in your poop.
Allergic colitis
This affects breastfeeding babies who have food to things like lactose or soy, which can be passed to them through breast milk. Colitis causes inflammation of the colon, which can trigger diarrhea with mucus.
Hemorrhoids
These are swollen veins that develop inside your rectum or around your anus. Also called piles, hemorrhoids can be painful and bloody. When they occur on your anus, they can swell and bulge outwards, and they can leak mucus, which you may notice on your stool or on your toilet paper.
Bowel obstruction
These can be partial or complete blockages of your large or small intestine, which prevent food and food waste (poop) from moving through your digestive tract. Partial blockages may allow liquid or mucus to pass. One type of bowel obstruction, called intussusception, causes rectal bleeding that may contain mucus.
Cystic fibrosis
This genetic disease causes thick and sticky mucus to build up in different parts of your body, including your lungs, where it blocks your airways and makes it difficult to breathe. It also can affect your digestive system. This can lead to severe constipation, gas, bloating, nausea, and loss of appetite. You may have mucus with your poop, which can be gray or the color of clay and smell very bad.
Mucus in Stool Diagnosis
To find the cause, your doctor will review your symptoms, your health history, and your family’s health history -- some diseases, including colorectal cancer, can run in families. They may also do testing, such as:
Fecal occult blood or fecal immunochemical test, which examines a small sample of your poop for tiny traces of blood that can’t be seen by the eye.
Stool culture and other stool tests, which are used to examine a small sample of your poop for signs of bacterial and other infections, inflammation, and problems with your pancreas.
Breath tests, which can help diagnose stomach problems such as bacterial infections.
Colonoscopy or sigmoidoscopy, in which your doctor uses a thin, flexible tube with a camera to look inside your colon. Both can identify the presence of suspicious growths, such as polyps, that could indicate cancer. This type of test also can be used to diagnose IBD.
Upper endoscopy, in which your doctor uses a camera mounted on a thin, flexible tube to check your esophagus, stomach, and the upper part of your small intestine.
Capsule endoscopy, in which you swallow a capsule that holds a camera. That capsule passes through your digestive system. It helps your doctor identify causes of bleeding in your small intestine and allows your doctor to look for signs of disease, such as cancer and Crohn’s disease.
X-rays, which are used as part of many different tests. These include computed tomography (CT), which combines X-rays and computers to create more detailed images than standard X-rays, and colorectal transit studies, which look at how food passes through your colon.
Magnetic resonance imaging (MRI), which uses radio waves and magnets to take detailed, three dimensional pictures of your organs and tissues.
Ultrasound, which uses sound waves to create images of your internal organs. It can help identify swelling or damage caused by illness as well as to monitor you if you have Crohn’s disease.
Treatment and Home Care for Mucus in Stool
The treatment you get for mucus in your poop depends on the problem that’s causing it. Some conditions will need medicine and others won't. For example, changes in diet that help you avoid certain foods may help you manage symptoms of IBS.
With mild food poisoning, you may only need to drink more fluids. On the other hand, you need antibiotics to treat infection with C. diff.
Once you have a diagnosis, you and your doctor should talk about the best treatment for your condition.
Takeaways
Mucus lubricates your colon so that food and food waste can pass through it easily. Sometimes, you may see mucus in your stool after using the toilet. This can happen for many reasons, some serious, others easily addressed. Talk to your doctor, who can determine the cause and what treatment, if any, you need.
