Rifaximin 200 mg Plus Oral Rehydration vs Oral Rehydration Alone in Children With Acute Diarrhea

This is a randomized, open-label study to assess the pharmacokinetics of Xifaxan® 200 mg in pediatric participants 6 to 11 years of age with acute diarrhea of suspected bacterial etiology, and safety and efficacy Xifaxan® 200 mg plus ORT compared to ORT alone. Participants will receive Xifaxan® 200mg (1 tablet) TID plus oral rehydration therapy (ORT) or ORT alone as per the Investigator's Standard of Care (SOC) for administering ORS for three days. Participants will complete 3 or 4 study visits during the study; Screening (Day -2 to Day 1), Day 1, Day 3 (End of Treatment), and Day 5 (Last Clinic Visit), and 2 safety follow-up phone calls; Once during Day 6 to 8, and on Day 30 (End of Study). Participants may complete both Screening and Day 1 on the same day. At the Screening visit, participants will provide a stool sample for PCR testing to identify the bacterial pathogen isolated. During the 5-day study period, the participant or their caregiver will complete a diary to record the dose, the time of dosing, time and consistency of stools, and incidence of symptoms as defined above. In addition, the participant or the caregiver will record any AEs in the eDiary from Day 4 to Day 30 with Day 1 to Day 3 assessed during study visits. Participants in the Xifaxan® 200 mg plus ORT arm will undergo two 6 to 8-hour pharmacokinetic sampling periods, the first following the first dose on Day 1 and the second following the first dose on Day 3. During these sampling periods, 3 blood samples (approximately 4 mL each) will be collected for analysis of rifaximin and 25- desacetyl rifaximin plasma concentrations at the following times: pre-dose, 1 hour (+/- 10 minutes) and no less than 6 but no more than 8 hours following the first dose of the day.