COLONIC TRANSIT TIMES AND THE EFFECT OF LACTULOSE OR LACTITOL IN HOSPITALIZED-PATIENTS

Objective: To investigate whether a small dose (10 g per day) of a lax ative (liquid lactulose, crystallized lactulose, or crystallized lacti tol) can prevent the slow colonic transit associated with the physical inactivity of hospitalization. Design: Patients were randomly allocat ed to one of four groups: control, liquid lactulose, crystallized lact ulose or crystallized lactitol, and the average of mean colonic transi t times in these groups was compared. Setting: Gastroenterologic Unit, Hospital dos Covoes, Coimbra, Portugal. Patients: Patients with norma l bowel movements, admitted to hospital for the investigation of condi tions not associated with constipation or diarrhoea, were allocated to one of the four treatment groups and had their mean colonic transit t imes studied after hospitalization using radiopaque markers and abdomi nal radiographs. Each study group had 18 patients. During the study, e ach patient was given a normal diet and no drugs except the relevant l axative. Results: The average of the mean colonic transit times in eac h of the four groups were: 52.16 h [95% confidence interval (CI) 39.42 -64.84] for controls; 22.45 h (95% CI 13.84-31.06) in the liquid lactu lose group; 24.05 (95% CI 12.13-35.97) in the crystallized lactulose g roup; and 35.95 (95% CI 23.82-48.08) in the crystallized lactitol grou p. The differences were statistically significant for the two lactulos e groups. The study of the mean colonic regional transit times showed that these differences related to transit in the right colon. Conclusi ons: A small dose of lactulose (either liquid or crystallized) was eff ective in preventing slow colonic transit and constipation in hospital ized patients without causing unwanted symptoms. The slow transit affe cted mainly the right colon, and it was in this region that the laxati ve had effect.