I would recommend following Dr. McDougall's elimination diet http://www.drmcdougall.com/med_allergic.html
It sounds like you have some food sensitivities, perhaps gluten is one since the wheat pasta set you off.
You may also benefit from a really good probitic such as Bio-k.
Stick to whole foods as much as possible, potatoes, sweet potatoes, brown rice, beans, lentils etc...limit the pastas, breads and such to give your body a break and let it heal. It will take time for your body to heal, it won't happen overnight.