I would recommend a huge look at your diet. What processed foods can you cut. What healthy foods, especially garlic, could you add. I put garlic especially because it has antibiotic properties and has helped my own tummy issues a ton. Garlic is miracle food in my opinion.
You might try earthclinic.com for some ideas of natural remedies also. Its one of the places I go but I research everything before I try any "cures". Some have worked very very well. I know Aloe juice is one mentioned. Its the only one I remember though. I ran across the Aloe juice reference while looking for something for acid reflux. I have only heard good things about it though from others. Aloe seems to be a pretty safe and mild fix too. My brother used it when he was battling some type of sever bacterial infection in his tummy.
You might also look to accupressure and Jin Shin Jyutsu. I go to a wonderful lady who has helped me so much with these. Many of these encourage and teach self help so they may be able to teach you ways to deal with pain, anxiety, and boost the immune system.