There are eight million stories in the naked city of how to manage, or mis manage, the "mostly empty rectum" requirement. This is one of them.
Everyone has their own formula. I tried to slip in a small amount of my usually large servings of greens and veggies. And took a GasX at night.
Or, go with the non-gas medical diet recommendation synopsis:
Double Whopper w/ cheese and fries, hold the lettuce and pickle, 3x daily.
Good luck. All of us struggle, but somehow figure it out and complete treatment. 😊