What Causes Recurrent Nausea?

My 81 yr old husband has experienced nausea on and off for many months but the last month has been constant. Our internist took of all end. And supplements for 2 wks. and gave him Zofran. He has just reintroduced 40 mg. Of Atorvastatin ( he s has been on cholesterol lowering med, niacin and Welchol also for 50 yrs.; also diltazam 180 mg. For afib; Namenda for dementia ( also had been on Exelon, but was taken off 2 was. Permanently); omprezole and Florastor ; baby aspirin ; vitamins. He is now on the Atorvastatin, aspirin,diltazam, Tagamet and zofran and the Dr. plans to check his Cholesteral in 2 mo.( he has familio hypercholestemia). The problem is none of what s being done has helped, he s been up and down and today the zofran isn t helping. He s is miserable and doesn t feel like eating. What can I do? Carol O.