Anyone that has chronic gastroenteritis please help!!!

I have gastroenteritis, have for years, I get what I call flare ups. It starts with eggy burps then after awhile the gas in my stomach is to much and I start puking and puking and even my puke smells like rotten eggs. I usually take milk of magnesia when it happens but it doesnt always work! And even when it does I'm still on the toilet for like 24 hours with diarrhea. Has anyone found anything that helps stop this when it does happen?!