Hello, Alaine.
I meet with a dietician regularly regarding my rising blood sugar levels (type 2 diabetes) who knew what a j pouch is and the problems associated with it, especially when diabetics are encouraged to eat fewer carbs, but a j poucher is encouraged to eat more starchy foods to thicken output. Contradictory.
If you are pre-diabetic you will, or already have, learned about the "plate" method to simplify the intake of vegetables, starch, and protein. Divide your plate into half. Fill one half with vegetables. Divide the other half into a further 2 sections, one section for a starch, the last section for a protein. That sounds easy if you are dealing with only diabetes and not an active pouch that doesn't like vegetables, or if you must be careful about the protein you take in because of your kidneys. I have to cook my vegetables very, very well so my pouch doesn't have to do a lot of work, and hopefully I can absorb some nutrients before they exit.
Try a smoothie from spinach, peeled apples, banana, almond milk? Google what proteins will cause the least overload on your kidneys and try to have that in a section of your plate. Eat complex carbs to keep your blood sugar from shooting up too quickly. Simple carbs will cause sugar spikes. I'm sorry that I don't know about kidney problems, but I wanted to give you some small suggestions to get your fruit and vegetables, and some encouragement, at least. If you can eat beans or chickpeas as your protein, try hummus on crackers or dipped with peeled cucumber -- this way the chickpea is already pulverized into tasty mush and your pouch might tolerate it well. Mine does, thankfully, and this is the protein section of my plate. I hope you find relief, and more suggestions.