In my opinion this is not a stomach ulcer. I believe that it would have been discovered through the endoscopy if an ulcer were present. An ulcer is simply an hole or beginning of a hole in the stomach lining. The test that would show an ulcer would be an Upper GI, were he would have to drink barium (a thick liquid) and be x-rayed. Biopsies are generally taken to find some sort of bacteria or other infections that are not visible with the naked eye. Judging from your brief description, he could have anything from a bacterial infection, to problems with his pancreas or gall bladder. But, it is too little information for me to judge what he has.