"Bring waterproof bandaids, antibiotic ear drops, oral antibiotics, antidiarrheals, cortisone cream (prescription strength if possible), patches if seasickness is a possibility, extra batteries for anything that uses batteries, including integrated-air sending units."
This is spot on. If I were coming to Indonesia for 2-3 weeks... Bring a Z-Pack and Imodium if you get sick. I have been here 16 years, and always use ear beer starting on day one no matter where I'm diving. If you really want to be safe, do not eat anything that hasn't been cooked or peeled- especially salads. Even at 5-star places, salads can get ya.