The efcacy of bismuth subsalicylate in the treatment of acute diarrhoea and the prevention of persistent diarrhoea HR Chowdhury 1 , M Yunus 1 , K Zaman 1 , A Rahman 1 , SM Faruque 1 , AG Lescano 2 and RB Sack 2 Public Health Sciences Division 1 , Internationa l Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh; Department of International Health 2 , Johns Hopkins University School of Hygiene and Public Health, Baltimore, Maryland, USA Chowdhury HR, Yunus M, Zaman K, Rahman A, Faruque SM, Lescano AG, Sack RB. The efcacy of bismuth subsalicylate in the treatment of acute diarrhoea and the prevention of persistent diarrhoea. Acta Pædiatr 2001; 90: 605–610. Stockholm. ISSN 0803-5253 A controlled, randomized, double-blind study in Bangladeshi children (ages 4–36 mo) with acute diarrhoea was undertaken to determine whether bismuth subsalicylate (BSS) would prevent the development of persistent diarrhoea (PD) in young children. The children were randomized to two groups: 226 were given liquid oral BSS, (as Pepto-Bismol), 100 mg/kg/d for 5 d; 225 were given placebo of identical appearance. On admission to the study, the two groups were comparable both clinically and microbiologically. Rotavirus was found in 56% of all the children, and enterotoxi- genic E. coli in 31% of a subsample studied. Children treated with BSS had less severe and less prolonged illness than those treated with placebo (p = 0.057). There was, however, no difference in the development of PD between the two groups (8% and 11%). Unexpectedly, patients treated with BSS gained signicantly more weight (2.3%) than those treated with placebo (0.5%; p < 0.001) during the course of the study. No toxicity of BSS was detected. Conclusion: Treatment with BSS had a modest therapeutic effect on acute diarrhoea, as has been previously demonstrated, but with no suggestion of a therapeutic effect on the prevention of persistent diarrhoea in this group of patients. Key words: Acute diarrhoea, bismuth subsalicylate, nutrition, persistent diarrhoea R Bradley Sack, Department of International Health, Johns Hopkins University School of Hygiene and Public Health, 624 N. Broadway, Baltimore, Maryland 21205, USA (Tel. ‡1 410 955 2719, fax. ‡1 410 502 6898, e-mail. rsack@jhsph.edu) Infectious diarrhoeal disease remains the second most common cause of death in children in the developing world despite the fact that simple, effective and inexpensive treatment is now possible (1). Mortality is due to: 1. dehydration secondary to the acute loss of water and electrolytes in stool; 2. to complications of invasive disease such as dysen- tery; 3. to the development of persistent diarrhoea (lasting ¶14 d). Oral rehydration therapy (ORT) and antimicrobials can effectively prevent death from dehydration or dysen- tery, but there is yet no universally effective therapy for persistent diarrhoea (PD). Although using means to avoid faecal contamination of food and water can prevent infectious diarrhoeas, these means will not come soon enough to most of the developing world. In contrast to our understanding of the pathophysiol- ogy of watery diarrhoea and dysentery, PD, which develops following an episode of acute diarrhoea, is poorly understood, both in terms of mechanisms and prevention. Although certain infectious agents have been associated with the development of PD (2–4), in most cases the causes are unknown. Dietary treatment has been shown to be partially effective (4–6), but antibiotics in general have usually not proven to be effective (7). It is estimated that approximately 3–7% of children in the developing world who experience acute diarrhoea or dysentery will have a prolonged episode of illness lasting 14 d or longer, which has become the recognized criterion for the diagnosis of PD (8). This prolongation of diarrhoea has a marked, negative effect on nutrition, is associated with a prolonged need for medical care and causes signicant mortality (4). Recent studies have shown that bismuth subsalicylate (BSS) is effective in shortening the length of acute diarrhoeal illness in small children in Chile (9) and Peru (10). In the latter study, there was a suggestion that the use of BSS was associated with fewer children developing prolonged diarrhoea. For this reason, it was thought that a larger study was warranted to determine whether BSS might prevent the development of persistent diarrhoea. We present the results of this Ó 2001 Taylor & Francis. ISSN 0803-5253 Acta Pñdiatr 90: 605±610. 2001