Impaction

Description and Causes
Assessment of Impaction
Treatment of Impaction
Current Clinical Trials

Five major factors can cause impaction:

1. Opioid pain medications.
2. Inactivity over a long period.
3. Changes in diet.
4. Mental illness.
5. Long-term use of laxatives.

   Regular use of laxatives for constipation contributes most to the development of constipation and impaction. Repeated use of laxatives in higher and higher doses makes the colon less able to signal the need to have a bowel movement. (See the Constipation section for causes of constipation that can result in impaction.)

Patients with impaction may have symptoms similar to patients with constipation, or they may have back pain (the impaction presses on sacral nerves) or bladder problems (the impaction presses on the ureters, bladder, or urethra). The patient's abdomen may become enlarged causing difficulty breathing, rapid heartbeat, dizziness, and low blood pressure. Other symptoms can include explosive diarrhea (as stool moves around the impaction), leaking stool when coughing, nausea, vomiting, abdominal pain, and dehydration. Patients who have an impaction may become very confused and disoriented with rapid heartbeat, sweating, fever, and high or low blood pressure.

The doctor will ask questions similar to those in the Assessment of Constipation section and do a physical examination to find out if the patient has an impaction. The examination may also include x-rays of the abdomen and/or chest, blood tests, and an electrocardiogram (a test that shows the activity of the heart).

Impactions are usually treated by moistening and softening the stool with an enema. Enemas must be given very carefully as prescribed by the doctor since too many enemas can damage the bowel. Some patients may need to have stool manually removed from the rectum after it is softened. Glycerin suppositories may also be prescribed. Laxatives that stimulate the bowel and cause cramping must be avoided since they can damage the bowel even more.

Check NCI’s list of cancer clinical trials for U.S. supportive and palliative care trials about constipation, impaction, and bowel obstruction that are now accepting participants. The list of trials can be further narrowed by location, drug, intervention, and other criteria.

General information about clinical trials is also available from the NCI Web site.