my husband just had bypass surg on his leg anfter he seen med to be fine but that night he started feeling nauses by the next monring his stomach was very distended they said he had an illeous so they put and ng tube in and drained his smoachthe following dad y he felt much better and his belly went down and they pulled the tube and gave him a full liq. diet with in 2 hours of eating a half of cup of yogurt he felt very full again and his belly started to get distended again what do you think could cause is