Here's the deal, I'm training for my first half marathon and I'm up to 10 miles. But, once I hit around 5/6 miles my stomach starts to bloat (to the point it's VERY noticeable) and I'm in pain the rest of the way. Once I'm done, stretch, relax, etc... I pass gas (a bunch) and the pain subsides. Any ideas on what I can do so this doesn't happen? Thanks!