You may need to take a probiotic that specifically targets the issue of travelers diarrhea. When you don't have enough good bacteria in your gut, it increases the likelihood of diarrhea.
Make sure you get one for travelers diarrhea otherwise, most probiotics tend to have the opposite effect at moderate doses which would make it worse. Imodium ad also works wonders, it was created by taking properties of opiates such as codeine without the painkilling effects. Any form of opiates such as vicodin,codeine, morphine all have extreme constipation side effects. In your situation it would just make your normal again and you won't get constipation.
Hope this helps