Visiting new places means that your body has to get used to new surroundings, colder, warmer (stronger sunshine), higher altitude and different food than it is used to. For everyone this can mean something different. Some people adapt quick, others need more time, but in the end almost everyone gets used to their new surroundings. The most important thing is that you listen to your body. Take it easy the first few days and let your body slowly adapt to the new things you eat and the new surrounding you are.
Be also careful with using strong medicine against diarrhea like lopromide. Having diarrhea means often that you ate something wrong. If you don´t really have to travel, it is better to get rid off the wrong food instead of closing your body and let the bacteria do more damage inside.
Good medications against parasites are: Albendazol (200 mg), dos pills to be taken directly and dos pills of Pazidol (1000 mg), to be taken the next day after a good meal.
Good medicine against Giardia Lamblia parasites are: Secnidogol (brand name: Bianos). With this medicine you only have to take one time at ones, 4 pills of 500 mg before a meal.