The current randomized clinical trial was conducted to assess the safety and effectiveness of Entoban for treating patients of chronic diarrhea. The study enrolled 150 patients fulfilling the inclusion criteria, among them 95 were males and 55 were females. Written informed consent was obtained from all study participants. Metronidazole tablets (400 mg) were used in a control group for 7-10 days. The test group received Entoban capsule 400mg every 8 hours for five days. Primary outcome of the study was daily bowel frequency evaluation; the secondary outcome was evaluation of clinical symptoms including abdominal pain, distention, stool consistency and sensation of incomplete evacuation. The study is registered at (https://register.clinicaltrials.gov) having registration number NCT02642250. In an intention-to-treat (ITT) analysis, it has been observed that 39(84.78%) in test group and 37(78.72%) in control group showed complete improvement. Participants in the test group exhibited a marked reduction in symptoms; the symptom score was decreased from 3 (maximum) to 1 (minimum) or 0 (absent) in most of participants. Major difference was observed regarding side effects reported between two treatment groups (p value <0.0001). Entoban possesses considerable therapeutic efficacy for the treatment of chronic diarrhea analogous with the conventional Metronidazole therapy.