Even though K pouches and J pouches have different exits we all have the same pouches...if you are looking for a diet to reduce gas then it is a high protein diet that works best: meat, fish, chicken, eggs, sea foods, peanut butter (if you are not allergic) etc. They are the foods that worked best for me.
I slowly add in vegetables that agree with my pouch (potatoes, sweet potatoes, starches like rice or whole-grain breads (absorb fluids)
Fruits that work best are apples (applesauce), persimmons, pears...
I personally avoid mixing fruits and starches because I find them very gas-forming but other people have no problems.
My new 'happy snack' is a sliced banana with a tbls of peanut butter, a couple of cashews, and raisins. It hits the spot and has 0 refined sugar.
When my pouch is too liquidy I tend to eat more starches, when it is normal I eat more proteins.
As for vegetables (raw or cooked) that just depends on you and your plumbing!
Sharon