Diseases Associated With Mucus in the Bowel

The intestines produce mucus, which protects and lubricates the bowel. A small amount of mucus normally passes unnoticed in the stool. With certain diseases and conditions, bowel mucus production increases. Increased stool mucus appears as clear to white gel-like material, which may coat the stool. Blood or pus may be present along with increased mucus with certain bowel conditions. Accompanying signs and symptoms help narrow the possible causes of increased mucus in the bowel. If you have concerns about mucus in your stool, contact your doctor.

Inflammatory Bowel Disease

Inflammatory bowel disease, which includes ulcerative colitis and Crohn disease, often causes increased bowel mucus. Blood is also commonly present in the stool with these diseases. Chronic bowel inflammation characterizes ulcerative colitis and Crohn disease. With ulcerative colitis, the disease remains limited to the colon, or large bowel. Crohn disease typically affects both the small and large bowel. Other possible symptoms of inflammatory bowel disease include:

  • diarrhea
  • abdominal pain
  • weight loss
  • fatigue
  • loss of appetite
  • nausea
  • vomiting
  • sporadic fever

Joint pain, skin rashes and visual disturbances may occur in some people with inflammatory bowel disease.

Irritable Bowel Syndrome

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What Are the Causes of Mucus in Stool?

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Irritable bowel syndrome, or IBS, is a common cause of increased bowel mucus. Despite the similar names and some overlapping symptoms, IBS is distinctly different from inflammatory bowel disease. With IBS, the bowel remains structurally normal with no evidence of chronic inflammation or other tissue abnormalities. IBS involves a functional abnormality in which the colon is periodically overactive or underactive: overactivity of the colon leads to diarrhea and underactivity causes constipation. People with IBS may cycle between episodes of diarrhea and constipation, often with normal bowel function between episodes. Cramping abdominal pain and bloating commonly accompany an episode of IBS. IBS with constipation often causes increased stool mucus. The absence of blood in the stool helps distinguish IBS from inflammatory bowel disease.


Dysentery is a medical term that encompasses a variety of bowel infections characterized by frequent painful bowel movements and watery stools containing mucus, blood, pus or a combination of these elements. Certain species of bacteria and single-celled parasites remain the most frequent causes of dysentery.

Pseudomembranous colitis, a form of dysentery caused by the bacterium Clostridium difficile, commonly affects debilitated patients who have recently taken antibiotics. The antibiotics kill normal colonic bacteria, creating an opportunity for C. difficile overgrowth. Dr. Michael Schroeder reports in a 2005 article published in American Family Physician that approximately 3 million cases of C. difficile intestinal infections occur annually in the United States.