I've never had that problem with Soya milk but if you've recently started drinking it, it could be because it is cleaning out your system and your colon in particular. If you eat meat you will have it rotting in your system so that soya will react with that too. You should do a no:2 twice a day, and once your system gets used to it, flatulence should reduce
Or try rice or oat milk (although soya is nice and creamy) which you system will probably be used to already and almond milk (gorgeous) for something sweeter. I wouldn't recommend coconut milk as too much can be a laxative. All of those non-dairy milks though benefit from almost no fat (even the chocolate, strawberry, vanilla and whatever other ones), no cholesterol, no lactose, don't need sugar added to them, can be used in drinks/cooking, are much healthier for you and taste better.
