Study of Nitazoxanide in the Treatment of Amebiasis in Adults and Adolescents

Inclusion Criteria: Age ≥12 years. Patients with diarrhea (≥3 bowel movements/day) with one or more enteric symptoms such as bloody stools, rectal bleeding or enlarged colon. Positive stool ELISA test for Entamoeba histolytica within 7 days prior to enrollment. Exclusion Criteria: Patients with identified causes of diarrhea other than E. histolytica. Use within 2 weeks of enrollment of any drug or therapy with possible anti-protozoal activity. Females who are pregnant, suspected of being pregnant or breastfeeding. Serious systemic disorders incompatible with the study. History of hypersensitivity to nitazoxanide. Patients in whom the possibility of receiving placebo and not being able to receive immediately an effective treatment will be incompatible with the severity of the patient's illness. Patients with amebic liver abscess. Patients known to have or suspected of having AIDS. Patient with immune deficiencies.