Thanks for your reply. I have no experience at all with permanent ostomies, only with a temp ileostomy. I think you would be better off listening to people with permanent ostomies, but I can mention a few things here that pertained to my temp ileo.
1. Size of meals - I was told to have only small meals (snacks) 3 to 5 times a day, but never a big meal. Big meals, especially at night, can cause the stoma bag to reach capacity and burst in the middle of the night. I also learned, by experience, to always avoid drinking carbonated beverages because they generate a lot of gas in the bowel and tend to push stool out faster than normal, and they also fill the stoma bag quickly with gas.
2. Parastomal hernia - If a hernia has already developed, it may be possible to get some relief by getting an abdominal binder that is especially designed with a circular hole to surround and support the ostomy device.
As for having hernia-repair surgery with a permanent ostomy in place, I wouldn't know what to say. My own parastomal hernia, which was quite large, was repaired eventually at the same time and in the same surgery when my temp ileostomy was finally removed.
For your husband, I think the best thing right now would be to get a well-fitted ostomy belt to prevent the hernia from getting any larger.