Mucus in Stool

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What is mucus in stool?

Mucus is a smooth, thick substance produced in many places throughout the body, including in the lining of the digestive tract. Mucus lubricates surfaces and allows materials to pass smoothly. Some amount of mucus in the stool is normal; however, significant amounts of mucus and mucus accompanied by diarrhea, pain or blood may signify an intestinal condition such as infection or inflammation. Increased amounts of mucus in the stool can also occur with cancers of the colon or rectum or with bowel obstruction.

Inflammatory conditions of the bowel, such as ulcerative colitis and Crohn’s disease, can cause abdominal cramping and bloating. Diarrhea is common with these conditions, although constipation can also occur. In addition, blood may be present in the stool as a result of ongoing damage to the intestinal lining.

Similar symptoms can occur with irritable bowel syndrome; however, since it is not an inflammatory condition and the lining of the intestine remains intact, blood in the stool is rare with this condition. When associated with a gastrointestinal infection, mucus in the stool often accompanies diarrhea and abdominal cramping. You may also have blood in the stool and a fever.

Conditions of the anus and rectum such as anal fissures (tears or cracks), anal fistulas (abnormal holes or tubes between organs or tissues), and rectal ulcers can also cause mucus in the stool. In such cases, the stool may appear normal or may be bloody. Pain with passing stool may become significant enough that you avoid bowel movements, which can lead to constipation and possible fecal impaction.

Increased amounts of mucus in the stool or mucus in the stool accompanied by other symptoms can be an indication of a serious medical problem. Seek immediate medical care (call 911) if you have a high fever or bloody stool, or if you develop symptoms of dehydration such as decreased urination, dark urine, increased thirst, fatigue, and light-headedness.

If mucus in your stool is persistent, especially if it is accompanied by other changes in your bowel movements or fever, or if it worsens or causes you concern, seek prompt medical care.

What other symptoms might occur with mucus in stool?

Mucus in stool may accompany other symptoms, which vary depending on the underlying disease, disorder or condition. Symptoms that frequently affect the digestive tract may also involve other body systems.

Digestive tract symptoms that may occur along with mucus in stool

Mucus in the stool may accompany other symptoms affecting the digestive tract including:

  • Abdominal pain or cramping

  • Abdominal swelling, distension or bloating

  • Abnormally foul-smelling stools

  • Bloody stool (the blood may be red, black or tarry in texture)

  • Changes in stool color or consistency

  • Diarrhea

  • Fecal incontinence (inability to control stools)

  • Gas

  • Nausea with or without vomiting

  • Painful bowel movements

  • Urgent need to pass stool

Other symptoms that may occur along with mucus in stool

Mucus in the stool may accompany symptoms related to other body systems including:

Serious symptoms that might indicate a life-threatening condition

In some cases, mucus in stool may be a symptom of a life-threatening condition that should be immediately evaluated in an emergency setting. Seek immediate medical care (call 911) if you, or someone you are with, have any of these life-threatening symptoms including:

  • Bloody stool (the blood may be red, black or tarry in texture)

  • Change in level of consciousness or alertness, such as passing out or unresponsiveness

  • Change in mental status or sudden behavior change, such as confusion, delirium, lethargy, hallucinations and delusions

  • High fever (higher than 101 degrees Fahrenheit)

  • Not producing any urine, or an infant who does not produce the usual amount of wet diapers

  • Pus in the stool

  • Rapid heart rate (tachycardia)

  • Rigidity of the abdomen

  • Severe abdominal, rectal or anal pain

  • Vomiting blood or rectal bleeding

What causes mucus in stool?

The digestive tract normally produces some mucus to help digested food and waste slide through it. Abnormal amounts of mucus in the stool may be caused by a variety of conditions ranging from inflammation and infection to obstruction and cancer.

Digestive tract causes of mucus in stool

Mucus in stool may be caused by digestive tract conditions including:

Serious or life-threatening causes of mucus in stool

In some cases, mucus in the stool may be a symptom of a serious or life-threatening condition that should be immediately evaluated in an emergency setting. These include:

  • Bowel obstruction

  • Colonic volvulus (twisting of the colon)

  • Intussusception (telescoping of the intestines into themselves, which can reduce blood supply, cause obstruction, and tissue death)

Questions for diagnosing the cause of mucus in stool

To diagnose your condition, your doctor or licensed health care practitioner will ask you several questions related to your mucus in stool including:

  • When did you first notice mucus in your stool?

  • Have you noticed any other changes in your stool or bowel habits?

  • Are you having pain or discomfort anywhere?

  • Do you have any other symptoms?

  • Have you noticed anything that makes it better or worse?

  • Have you recently eaten or drunk anything that is unusual for you?

  • Is there any possibility you may have eaten spoiled food?

  • Do you have symptoms more frequently when you eat certain types of foods?

  • What medications are you taking?

What are the potential complications of mucus in stool?

Because mucus in the stool can be due to serious diseases, failure to seek treatment can result in serious complications and permanent damage. Once the underlying cause is diagnosed, it is important for you to follow the treatment plan that you and your health care professional design specifically for you to reduce the risk of potential complications including:

  • Anemia (low red blood cell count)

  • Bowel obstruction, perforation or infarction (severe injury to an area of the bowel due to decreased blood supply)

  • Dehydration and electrolyte imbalance due to long-term diarrhea

  • Spread of cancer

  • Spread of infection

  • Surgery to remove parts of the digestive tract due to obstruction, rupture, serious infection, or malignant condition

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Nov 2
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
  1. Diarrhea. MedlinePlus, a service of the National Library of Medicine National Institutes of Health.
  2. What I need to know about Irritable Bowel Syndrome. National Digestive Diseases Information Clearinghouse (NDDIC).