Does he remember when his problem started ? like after having heavy meals or having fatty foods in the restaurants,etc apart from eating peas?
Apart from nausea, does he get any pain and which side is the pain ?
Please do Hida scan for gallbladder function and Ultrasound for gallstones.
while doing endoscopy did the doctor check for Lower espohagus spinchter tighness and did they do biopsies to rule out H .Pylori ,ulcer ,etc ?
when doing colonoscopy , they can rule out celiac diesease,etc .
if all the above tests are normal. Then the only option is to have a food diary and see which triggers the digestive problems and avoid those foods.
also like to share my story, may be useful .When i was in 20's i used to get lot of acid reflux, i use to take antiacid and things will resolve quickly, then around 26 years was having digestion issues,burping and bloating and left side gastric pain , endoscopy results got gastritis, ultrasound for gallbladder was normal. took omeperzole, around 29 i started getting discomfort and dull ache on right side which is gallbladder,did Hida scan and my gallbladder was working at 0%. Surgeon asked to remove, but did not remove and was on strict diet avoiding junk/fatty/oily/protein foods but still was suffering with bloating and fullness , but somewhat under control and things started to improve , then ended up eating in restaurants every week which ended up in gallstones.Did not remove my gb yet.I'm 37 male right now.I have severe bloating,fullness and dizzy with whatever i eat. This is my current situation.My surgeon feels i may still have issues after gb removal as i also have gastirits, so still in sidelines.
so hida scan was the game changer for me , but i never know if PPI like omeperzole made my gallbladder to not function or not.I highly suggest to do ultrasound and hida scan and avoid taking omperzole until the tests are completed.
if you see only gallbladder is the issue, then please remove it .I cannot put in details the sufferings i have gone through from 2011 to 2017 with the non working gb.
Hope your boyfriend gets better and he is really lucky to have girlfriend like you who really cares about him, bcoz many dont really or understand how it feels.