HI Well come to HCM Appreciate this Intestinal infection need to be differentiate as long as the causative organisms are concern because these could be, parasites, Bacteria, viral, or some lesion without infection and treatment could be suggested or taken into consideration accordingly, and for that some investigations may need, at the most condition can be managed on tentative basis with broad spectrum antibiotic and best option would be Trimethoprim and Sulfamethaxazole in double strength (drug is highly known for hypersensitivity reaction ), twice in day for vomiting Tab Domperidone can be tried 30 mg three times in day, hope this information helps, take care.