Four years ago I was discharged from the hospital without a third of my GI track. The sigmoid was gone and most of my ileum had been removed because my pelvis had received radiation in the 80's. Dead and scar tissue had been removed from the GI track that had been radiated.
I now live with a forever ostomy. Without the ileum my diet means limited nuts, seeds and no skins. Fruits have to be peeled, so I eat canned or dried. Tomatoes need to be peeled and seeded. Beans are iffy, corn has to be white young corn. No corn on the cob or yellow corn, my body cannot process it. Animal flesh is hard to process, I can do eggs and yogurt. Yogurt is my go to food, without the added fruits. If I want fruit I will add it myself, without the sugar. With an ileostomy foods are not fully processed so I take pills or shots to make sure I get the vitamins and minerals I need.
If your husband wants to loose weight the best way is not a diet but a forever lifestyle. It will be heavy in fruits and vegetables, low in fat, sugar, and sodium. Pasta and animal protein are limited to a small portion of your intake. Beef should be limited to once a week or every other week, fish, chicken or turkey can fill in the rest of the week.
When my urine is strong that means I am not getting enough water. Water should always be our beverage of choice, minimum 8-8oz glasses each day. Everything else has something added to it that is not good for the body.
If you can accept that you have a new lifestyle and it will be forever, your body will be happy. If your body is happy you will be happy. Good luck.