Gallbladder Post- Removal Surgery

I am worry about my dad, he had his Gallbladder Removal Surgery about 2 years ago, but still  he is not eating at all, very little, here and there, the nauseas and vomiting comes once in a while, i was just wondering what could he take to gain his appetite back, gain some weight, and start eating more...
Can anybody shed a light, please, are there some sort of vitamins, traditional medication treatment, (green ones), anything at all...Thanks

[CalGal]

Following a low fat diet may be of help as some people cannot process fatty foods as they did before gallbladder surgery.

But if your father is having pain and constant problems, he should see his doc and ask to have an MRCP done to make sure there are no stones or sludges in the common bile duct. Also make sure his liver and pancreatic enzyme levels are checked. Problems can occur after GB surgery and continuing issues need to be investigated.