oh my! sounds like he's overloaded his liver and bowels so much that they are constantly putting pressure on his pancreas. A thorough
Bowel Cleanse with both an oxygen-based cleanser like Colosan and enemas/colonic irrigations would be the best way to begin, switching to fiber shakes after the bottle of Colosan is gone, and concurrently a comprehensive
Liver Cleansing program altho i'm not sure he's safe to flush yet.
It would be safest to just fast for at least 3 days, not a complete
Water Fast but a broth/herbal tea/cleansing drink fast. ginger, peppermint, chamomile teas would be best. Valerian is great for pain.
A low-fat diet may help the pain, but it will cause even worse problems later on due to the liver getting stagnant and making more
liver stones . The liver and gallbladder are designed to be used, if they are not used, don't release bile, then the liver cannot release all the dreck that it removes from our bloodstream and we get jaundice and brain fog and this puts more pressure on the pancreas.
After a period of cleasning some rebuilding will be necessary. Skinfood and adrenal food especially, and a long period of digestive enzyme supplementation.
For the pain, a much safer intervention is the castor oil pack. You soak a flannel cloth with castor oil, heat it up in the oven, put it over the abdomen, wrap up in pastic and put a heating pad over that. It does wonders for pain! Peppermint tea should be a big help too.
It's also important that he release and detach from anger, any emotional addictions.
Good luck! :)