How To Cure Gastroenteritis?

I'm a 26-year-old 5'7" 150lb male. I've been diagnosed with gastroenteritis in the past, along with what the gastroenterologist described as "a touch" of colitis (whatever that means). For almost the past three years now (starting in May 2008), I've woken up every morning with nausea that will lead to vomiting about 10-20% of the time. I have a BM right when I wake up like clockwork and feel no relief after this (still sick to my stomach, still throw up). Diet changes (including when and what I eat) haven't fixed the problem nor have any of the meds the doctor put me on. It's affecting my work and school life now and is aggravating me to no end. What can I do to remedy this situation, because at this point, I'm willing to tear out my entire digestive system if it will bring one morning where I'm not waking up at 6 o'clock to run to the bathroom then sit in front of a garbage can for a few hours until I feel better. Thank you.