PIP: 2 antimicrobial agents, paromomycin, an antibiotic, and a sulfonamide, sulfamethoxypyridazine, were tested as supplement therapeutic treatment together with rehydration and nursing care in 535 cases of acute diarrheal disease in a Guatemalan highland village. All cases were under 5 years of age. 417 cases were bacteriologically tested, and 18% suffered from a recognized bacterial pathogen (Shigella or E. coli) and 82% were not. Cases occurred in 2 villages in the period from October 1960-December 1961. In 1 village, patients were treated with the antimicrobial agents in addition to general medical care; in the other, cases were treated with family nursing and folk remedies only. The general death rate from all causes was lower in the village where general medical care was provided. Deaths from acute diarrheal disease were relatively few in both villages. An annual mortality from diarrheal disease of 7.7 per 1000 children in the treated community and of 17.3 in the untreated community was reported. The difference, however, was attributed mostly to general supportive measure, especially rehydration and nursing care. In vitro, paromomycin was very effective, but it did not prove so clinically. The sulfonamide was effective against only 61% of Shigella strains in vitro, and the clinical result was somewhat less.