If a diagnosis of fecal impaction is uncertain, a laboratory workup can rule out other problems. A complete blood cell count, appropriate blood chemistries, chest x-ray, and an electrocardiogram can be performed. If the patient has become dehydrated, the blood urea nitrogen, creatinine, and serum osmolality will be elevated. There may be an elevation of the hemoglobin and hematocrit indicating hemoconcentration. The white blood cell (WBC) count may be slightly elevated in the presence of a fever. If the WBC count is extremely elevated and the patient is exhibiting a high fever and abdominal pain, an obstruction, perforation, infection, or inflammatory process must be ruled out. With marked distention of the cecum (diameter ≥12 cm), there is a risk of bowel perforation.
Treatment of Impaction
The primary treatment of impaction is to hydrate and soften the stool so that it can be removed or passed. Enemas (oil retention, tap water, or hypertonic phosphate) lubricate the bowel and soften the stool. Caution must be exercised; fecal impaction can irritate the bowel wall, and enemas in excess may perforate the bowel. The patient may need to be digitally disimpacted if the stool is within reach. This is best done after administering an enema to lubricate the bowel.
Nonstimulating bowel softeners such as docusate can be used to help soften stool higher in the colon. Mineral or olive oil can be given to loosen the stool. Caution should be used when giving docusate sodium with mineral oil because there could be an increased systemic absorption of the mineral oil leading to systemic lipid granulomas. Glycerin suppositories can also be used. Any laxatives that might stimulate the bowel or cause cramping should be avoided so that the bowel is not damaged further.
Current Clinical Trials
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.
Cefalu CA, McKnight GT, Pike JI: Treating impaction: a practical approach to an unpleasant problem. Geriatrics 36 (5): 143-6, 1981.
Bruera E, Suarez-Almazor M, Velasco A, et al.: The assessment of constipation in terminal cancer patients admitted to a palliative care unit: a retrospective review. J Pain Symptom Manage 9 (8): 515-9, 1994.
Brandt LJ: Gastrointestinal Disorders of the Elderly. New York, NY: Raven Press, 1984.