My Son Is 38 Yrs Old, Had Constant Hiccups For

My son is 38 yrs old, had constant hiccups for about a month prior to having exploratory surgery, an access was found on his colon. Surgeon cleaned it out, followed with antibiotics. Three weeks later same symptoms returned along with burping. Back in the hospital to have gall bladder removed. It's been several weeks now, he is hiccupping constantly and burping also for a week. Cannot figure out why hiccups and burping returned?