I am not a doctor, but I am majoring in biology. And what I suggest is your husband, of course, see a doctor. If you are really concerned about him having ulcers, he should get a biopsy. However, ulcers are not caused by stress or any of those other myths. Ulcers are caused by the bacterium helicobacter pylori. And even if he has an ulcer, a strong combination of antiobiotics (bismuth, etc) should potentially kill the bacteria.
It's also always good to know what he's eating. Perhaps he should keep tabs on a food journal.