What are the Most Common Causes of Mucus in Diarrhea?

The most common causes of mucus in diarrhea are ulcers that have become inflamed, a condition which is known medically as ulcerative coilitis, and infections somewhere along the intestinal tract. In some cases irritable bowel syndrome could be a cause, too, and more rarely obstructions or growths are to blame. A small amount of mucus isn’t always a cause for concern in and of itself. Medical experts usually recommend that people get checked out if the problem is recurring, though, or if a lot of mucus seems to come out with each expulsion. Persistent mucus-laced diarrhea could be a sign of a serious problem, and prompt treatment is often essential when it comes to finding a cure.

Humans and many animals produce mucus in a couple of different parts of the body, most often as a means of facilitating cellular movement. It’s commonly seen during respiratory illnesses, when the sinuses and lungs produce it to help flush out bacteria and harmful particulates. Healthy people also make it in their digestive tracts, though, and it has an important role to play when it comes to helping move solid waste through the intestine and eventually out the rectum. Diarrhea generally is a sign of some intestinal distress, though, and the presence of mucus often signals that there may be a bigger problem. At the same time, in some cases it’s simply a symptom of the irritation, and will go away on its own as the diarrhea passes.

Diarrhea that lasts for more than a few days is usually a cause for concern, especially if it has visible amounts of mucus in it. Ulcerative colitis (UC) is one of the most common causes. In these cases, the mucus results from inflammation in the colon, which can lead to an ulcer. Ulcers are basically sores or patches of weakened, damaged tissue that become so irritated they can’t heal. The intestines will make often make extra mucus to protect these areas, but it doesn’t always work. If the ulcers rupture, they can leak pus and sometimes also blood into the stool.

Inflammation can also happen because of an infection somewhere in the intestines. This can happen as a result of injury or accident, but might also be caused by eating foods that contain harmful bacteria or that haven’t been cooked or cleaned properly. Diarrhea and mucus overproduction generally both subside once the immune system takes care of the underlying infection, but depending on how bad it is this could take awhile.

Irritable bowel syndrome (IBS) is a chronic condition that often causes diarrhea, constipation, gas, bloating, and stomach pain. Mucus in diarrhea is common for many IBS patients, at least at times. IBS is sometimes difficult to diagnose and treat because of how much a person’s symptoms can change from day to day. There’s isn’t normally a cure, but there are many things people can do to alleviate the biggest discomforts. Most center on changes to diet and exercise.

Bowel obstructions might also cause mucus to be released with diarrhea. Sometimes the obstruction is stool-related, as is the case with extreme constipation; in these cases diarrhea often happens as a means of getting something out around the mass, and mucus is often generated to help try and force the mass out. The two can get mixed relatively easily.

Growths are another possibility. Tumors or cysts that form on the intestinal walls might trigger excess mucus production. This often happens in cases of colon and colorectal cancers. Each is relatively rare, and in most cases there are many other symptoms besides just mucus. Still, this is often one of the first signs a person gets that something isn’t quite right inside.

People who experience diarrhea mixed with mucus should usually get a medical opinion, particularly if the condition lasts for more than a few days. It may go away on its own, but if it doesn’t getting help may be the best course. Prolonged diarrhea, with or without mucus, is usually considered problematic from a medical standpoint, and getting to the root of it sooner rather than later can make treatment easier — and in some cases can actually be life-saving.