Acute infectious diarrhea (AID) represents an important clinical entity both regarding morbidity and mortality rates, even in industrialized countries, and it leads to one of the major public health burdens, among gastroenterological diseases, with significant healthcare costs. Oral rehydration solution is the cornerstone of the therapy, but despite its proven efficacy in avoiding dehydration, it is still underused as it does not reduce the duration of diarrhea; hence, it is perceived as ineffective by caregivers. In this narrative review, we collected literature regarding the use of racecadotril, deeply discussing its role in the treatment of AID in both adults and children. Racecadotril has been studied in wide populations of patients, in many countries, and in different clinical settings. Its effectiveness in reducing the stool output and the duration of diarrhea has been proven, not only in the early phase of the disease. Racecadotril has been shown to increase the likelihood of home management of AID, to reduce hospitalizations and parenteral rehydration needs resulting in healthcare costs reduction. The current new formulations require only two-daily doses for adults and the pediatric syrup should simplify its use.