Double blind trial of loperamide for treating acute watery diarrhoea in expatriates in Bangladesh.

To determine if loperamide is effective and safe in treating watery diarrhoea, we randomly assigned 50 adult expatriates in Bangladesh with more than three unformed stools in the previous 24 hours and illness of less than 72 hours to receive loperamide or a placebo. On entry into the five day study patients took two capsules (one loperamide capsule = 2 mg) and one after each unformed stool up to a maximum of eight per day. The groups did not significantly differ in pretreatment features or pathogens identified. Mean number of stools on study day 1 was 2.6 in the loperamide group and 4.0 in the placebo group (p = 0.035); on day 2 it was 1.3 versus 3.4 (p less than 0.001). Differences in stool frequencies during the final three study days, or proportion of patients with cramps, nausea, or vomiting on any study day, were not significant. No serious side effects occurred in either group. We conclude that loperamide, by decreasing stool frequency during the early part of illness, may have a role in the symptomatic treatment of this self-limiting disease.