A fecal impaction is a large lump of dry, hard stool that stays stuck in the rectum. It is most often seen in people who are constipated for a long time.
Impaction of the bowels
Constipation is when you are not passing stool as often or as easily as is normal for you. Your stool becomes hard and dry, and it is difficult to pass.
Fecal impaction often occurs in people who have had constipation for a long time and have been using laxatives. The problem is even more likely when the laxatives are stopped suddenly. The muscles of the intestines forget how to move stool or feces on their own.
You are at more risk for chronic constipation and fecal impaction if:
You not move around much and spend most of your time in a chair or bed.
You have a disease of the brain or nervous system that damages the nerves that go to the muscles of the intestines.
Certain drugs slow the passage of stool through the bowels:
Anticholinergics, which affect the interaction between nerves and muscles of the bowel
Medicines used to treat diarrhea, if they are taken too often
Narcotic pain medicine, such as methadone and codeine
Common symptoms include:
Abdominal cramping and bloating
Leakage of liquid or sudden episodes of watery diarrhea in someone who has chronic constipation
Small, semi-formed stools
Straining when trying to pass stools
Other possible symptoms include:
Bladder pressure or loss of bladder control
Lower back pain
Rapid heartbeat or light-headedness from straining to pass stool
Exams and Tests
The health care provider will examine your stomach area and rectum. The rectal exam will reveal a hard mass of stool in the rectum.
If there has been a recent change in your bowel habits, your doctor may recommend a colonoscopy to check for colon or rectal cancer.
Treating a fecal impaction involves steps to remove the impacted stool. After that, measures are taken to prevent future fecal impactions.
Often a warm mineral oil enema is used to soften and lubricate the stool. However, enemas alone are usually not enough to remove a large, hardened impaction.
The mass may have to be broken up by hand. This is called manual removal:
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 come out.
This process must be done in small steps to avoid causing injury to the rectum.
Suppositories inserted into the rectum may be given between attempts to help clear the stool.
Surgery is rarely needed to treat a fecal impaction. An overly widened colon (megacolon) or complete blockage of the bowel may require emergency removal of the impaction.
Most people who have had a fecal impaction will need a bowel retraining program. Your doctor and a specially trained nurse or therapist will:
Take a detailed history of your diet, bowel patterns, laxative use, medications, and medical problems
Examine you carefully.
Recommend changes in your diet, how to use laxatives and stool softeners, special exercises, lifestyle changes, and other special techniques to retrain your bowel.
Follow you closely to make sure the program works for you.
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
Lembo AJ, Ullman SP. Constipation. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 9th ed. Philadelphia, PA: Saunders Elsevier; 2010:chap 18.
Madoff RD. Diseases of the rectum and anus. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 147.
George F. Longstreth, MD, Department of Gastroenterology, Kaiser Permanente Medical Care Program, San Diego, California. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.