Final answer:
The drug of choice for trichomoniasis is metronidazole, while the drug of choice for IBD and intestinal amebiasis may vary depending on the specific condition.
Step-by-step explanation:
The drug of choice for trichomoniasis is metronidazole. For inflammatory bowel disease (IBD), the drug of choice depends on the type of IBD, but options may include aminosalicylates, corticosteroids, immunomodulators, or biologic agents. For intestinal amebiasis, the drug of choice is metronidazole.