Fecal impaction

Alternative names

Impaction of the bowels

Definition

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)
  

Symptoms
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

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:

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:

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.