Treatment of constipation with sorbitol

Nutrition Research Newsletter, Jan, 1991 by Frank A. Lederle

TREATMENT OF CONSTIPATION WITH SORBITOL The drug lactulose, a nonabsorbable disaccharide that acts as an osmotic laxative, is an effective remedy for chronic constipation in the elderly. Its use, however, is limited by its high cost. Sorbitol, another nonabsorbable sugar with an osmotic laxative effect, is much less expensive. In this study, researchers from the Minneapolis Veterans Affairs Medical Center in Minnesota evaluated the use of sorbitol as an alternative to lactulose in chronically constipated elderly patients.

Thirty ambulatory men (aged 65 to 86 years) with chronic constipation received self-adjusted doses of comparable concentrations of lactulose and sorbitol for four weeks each with a two-week washout period before each treatment. The trial used a randomized, double-blind, crossover design. Patients were asked to maintain high dietary fiber and to avoid sources of free fructose> they were allowed to continue takin g bulk-forming agents throughout the study.

There was no significant difference between the two treatments in average number of bowel movements per week, average number of days per week with bowel movements, self-assessed severity of constipation, percentage of bowel movements recorded as "normal," or frequency and severity of symptoms such as bloating and cramping. Excessive flatulence was reported with both treatments, while nausea was increased with lactulose. "The 95% confidence intervals for these outcome measures exclude large clinically important differences between the two treatments." Eleven patients preferred sorbitol, 12 lactulose, and seven had no preference.

On the basis of this study, the authors conclude that "sorbitol can be recommended as an inexpensive alternative to lactulose for the treatment of constipation in the elderly," but they caution that the results may not apply to younger patients, to women, or to those who are bedridden.

Frank A Lederle et al, An Effective Treatment of Constipation in the Elderly: A Randomized Double-Blind Comparison of Sorbitol and Lactulose, American J Medicine 89(5):597-601 (Nov 1990) [Reprints: Frank A Lederle, MD, Division of General Internal Medicine (III-0), Department of Medicine, Minneapolis Veterans Affairs Medical Center, One Veterans Drive, Minneapolis MN 55417]