Impaction of the bowels

Alternative names
Fecal impaction


A fecal impaction is a large mass of dry, hard stool that can develop in the rectum due to chronic constipation. This mass may be so hard that it cannot be excreted. Watery stool from higher in the bowel may move around the mass and leak out, causing soiling.

Causes, incidence, and risk factors

Certain people are at greater risk for developing a chronic constipation, which can lead to fecal impaction. Patients at risk include those who:

  • Take certain drugs:       o Any type of narcotic pain medication       o Methadone maintenance treatment for narcotic addiction       o Anticholinergic medications       o Antidiarrheal medications  
  • Have decreased mobility  
  • Have a limited diet (especially one that is low in fluids)

Sudden, watery diarrhea in someone who has chronic constipation is usually an indication of a fecal impaction. Other symptoms include frequent straining with passage of liquid or small, semi-formed stools or abdominal cramping and discomfort.

Signs and tests

The health care provider will examine your abdomen and rectum. The rectal exam will reveal a hard mass of dry stool within the rectum.

If there has been a recent change in your bowel habits, your doctor may recommend colonoscopy to evaluate for colon or rectal cancer.


Treatment of a fecal impaction involves removal of the impacted stool, as well as measures to prevent constipation and further development of a fecal impaction.

Medications may be used to prevent further development of a fecal impaction. Stool softeners such as docusate may be recommended to aid in the passage of soft, formed stools. Additionally, bulk fiber laxatives such as Metamucil may be used to add fluid and bulk to the stool.

Glycerin or bisacodyl suppositories or other gentle laxatives may be used in conjunction with a bowel retraining program to establish a pattern of regular bowel movements. Nutritional adjustments may be helpful in those with a limited diet or immobility.

Surgery is rarely required to treat a fecal impaction. However, if the fecal impaction is not removed, the colon may become overly dilated (megacolon) or the bowel can become completely obstructed. Both of these conditions will require emergency surgery to remove the impaction and possibly part of the injured bowel.

Dietary measures such as increasing fiber intake from whole-wheat grains, fresh fruits and vegetables, and bran may help add bulk to the stool, thus promoting normal bowel movements. Special efforts should be made toward increasing daily fluid intake.

Regular exercise is very important in establishing regular bowel movements. People who are confined to a wheelchair or bed should change position frequently and perform abdominal contraction exercises and leg raises, if possible, several times throughout the day. A physical therapist can recommend a program of exercises appropriate for your physical abilities.

The treatment of fecal impaction is aimed at removing the fecal impaction and initiating a program to maintain normal bowel function. Often a warm mineral oil enema is used to soften and lubricate the fecal impaction. However, enemas alone are frequently not enough to remove a large, hardened impaction.

The mass may have to be manually broken up. A health care provider will need to insert one or two fingers into the rectum and slowly break up the mass into smaller pieces so that it can be expelled. Manual removal of a fecal impaction is usually performed in small steps to reduce the risk of injuring the rectal tissues. A series of suppositories may be given between manual removal attempts, to help clear the bowel.

Expectations (prognosis)
With treatment, the outcome is good.


  • Necrosis (tissue death) or rectal tissue injury  
  • Ulceration of the rectal tissue

Calling your health care provider

Notify your health care provider if you are experiencing chronic diarrhea or fecal incontinence following a long period of constipation. Also notify your health care provider if you are experiencing any of the following symptoms:

  • Sudden constipation with abdominal cramps, and an inability to pass gas or stool. (In this case, do not take any laxatives. Call your health care provider immediately!)  
  • Very thin, pencil-like stools.  
  • Abdominal pain and bloating.  
  • Blood in the stool


Prevention of fecal impaction centers on preventing constipation. Fiber should be added to the diet to promote normal stool consistency. Additionally, an adequate intake of fluids and exercise may enhance normal stool consistency.

Always respond promptly to the urge to defecate.

Johns Hopkins patient information

Last revised: December 3, 2012
by Gevorg A. Poghosian, Ph.D.

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