Gastrointestinal Complications (PDQ®): Supportive care - Patient Information [NCI] - Fecal Impaction

Fecal impaction is a mass of dry, hard stool that will not pass out of the colon or rectum.

Fecal impaction is dry stool that cannot pass out of the body. Patients with fecal impaction may not have gastrointestinal (GI) symptoms. Instead, they may have problems with circulation, the heart, or breathing. If fecal impaction is not treated, it can get worse and cause death.

A common cause of fecal impaction is using laxatives too often.

Repeated use of laxatives in higher and higher doses makes the colon less able to respond naturally to the need to have a bowel movement. This is a common reason for fecal impaction. Other causes include:

  • Opioid pain medicines.
  • Little or no activity over a long period.
  • Diet changes.
  • Constipation that is not treated. See the section above on causes of constipation.

Certain types of mental illness may lead to fecal impaction.

Symptoms of fecal impaction include being unable to have a bowel movement and pain in the abdomen or back.

The following may be symptoms of fecal impaction:

  • Being unable to have a bowel movement.
  • Having to push harder to have a bowel movement of small amounts of hard, dry stool.
  • Having fewer than the usual number of bowel movements.
  • Having pain in the back or abdomen.
  • Urinating more or less often than usual, or being unable to urinate.
  • Breathing problems, rapid heartbeat, dizziness, low blood pressure, and swollen abdomen.
  • Having sudden, explosive diarrhea (as stool moves around the impaction).
  • Leaking stool when coughing.
  • Nausea and vomiting.
  • Dehydration.
  • Being confused and losing a sense of time and place, with rapid heartbeat, sweating, fever, and high or low blood pressure.

These symptoms should be reported to the health care provider.

Assessment includes a physical exam and questions like those asked in the assessment of constipation.

The doctor will ask questions similar to those for the assessment of constipation:

  • How often do you have a bowel movement? When and how much?
  • When was your last bowel movement? What was it like (how much, hard or soft, color)?
  • Was there any blood in your stool?
  • Has your stomach hurt or have you had any cramps, nausea, vomiting, gas, or feeling of fullness near the rectum?
  • Do you use laxatives or enemas regularly?
  • What do you usually do to relieve constipation? Does this usually work?
  • What kind of food do you eat?
  • How much and what type of fluids do you drink each day?
  • What medicines are you taking? How much and how often?
  • Is this constipation a recent change in your normal habits?
  • How many times a day do you pass gas?


The doctor will do a physical exam to find out if the patient has a fecal impaction. The following tests and procedures may be done:

  • Physical exam: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual.
  • X-rays: An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body. To check for fecal impaction, x-rays of the abdomen or chest may be done.
  • Digital rectal exam (DRE): An exam of the rectum. The doctor or nurse inserts a lubricated, gloved finger into the lower part of the rectum to feel for a fecal impaction, lumps, or anything else that seems unusual.
  • Sigmoidoscopy : A procedure to look inside the rectum and sigmoid (lower) colon for a fecal impaction, polyps, abnormal areas, or cancer. A sigmoidoscope is inserted through the rectum into the sigmoid colon. A sigmoidoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer.
    Sigmoidoscopy. A thin, lighted tube is inserted through the anus and rectum and into the lower part of the colon to look for abnormal areas.
  • Blood tests: Tests done on a sample of blood to measure the amount of certain substances in the blood or to count different types of blood cells. Blood tests may be done to look for signs of disease or agents that cause disease, to check for antibodies or tumor markers, or to see how well treatments are working.
  • Electrocardiogram (EKG): A test that shows the activity of the heart. Small electrodes are placed on the skin of the chest, wrists, and ankles and are attached to an electrocardiograph. The electrocardiograph makes a line graph that shows changes in the electrical activity of the heart over time. The graph can show abnormal conditions, such as blocked arteries, changes in electrolytes (particles with electrical charges), and changes in the way electrical currents pass through the heart tissue.


A fecal impaction is usually treated with an enema.

The main treatment for impaction is to moisten and soften the stool so it can be removed or passed out of the body. This is usually done with an enema. Enemas are given only as prescribed by the doctor since too many enemas can damage the intestine. Stool softeners or glycerin suppositories may be given to make the stool softer and easier to pass. Some patients may need to have stool manually removed from the rectum after it is softened.

Laxatives that cause the stool to move are not used because they can also damage the intestine.

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