It may take a bit for his appetite to come back. The surgery and anesthesia alone will do that. Bowel surgery doesn't help either. It was months before I got my appetite back. Maybe some soft foods will help as well as protein drinks. Lots of protein will help him heal quicker as well. They had me on 120 g of protein a day based on my height and weight. I got some whey protein powder from Walmart and made protein smoothies 2-3 times a day.

I'm glad the ostomy nurse ordered the welcome kits for you. It's nice to have options to try and, like I mentioned, you can call the companies if you want to try other things.