Every year for the last 3 years, my son stomach starts to act up, makes him sick to his stomach and hard to eat. It seems like everything will upset his stomach. We have spent thousands in medical bills and have had numerous not so fun tests. trying to figure it out. It always starts in march and goes thru june. Any allergies that could cause this? He is 20, it started when he was 18 and he lost 20 plus pounds. I am just finding it odd it is the same time of year, every year. Any ideas?