Try two things:
#1 chew your food until it reaches liquid form.
#2 get hydrated approx 30 minutes before meals.
Chewing your food well is really helpful. The enzymes in your saliva start digesting the food, which gives your stomach less work to do. You will likely digest your food better.
I find that getting hydrated with water 15-30 minutes before meals really helps my "flow"... usually I'm in the bathroom 30 minutes after a meal.
Drinking water (or any beverage) with a meal dilutes your stomach acid. It also gives your mouth the tendency to swallow food before it's been pre-digested by your saliva.
(Obviously you don't need to get hydrated before you eat a salad or piece of fruit)
Edit: By "get hydrated," I mean take 3-4 large sips of water. Not a whole lot.