Bloating, Bad Bowel Habits. Situation.

I have a history of peptic ulcers. They were diagnosed last time some 5 to 6 years back. Colonoscopy was also done, but was clear. Now, I have this chronic problem of Bloating, Heatburn, Stomach Gas, and what not.. Stool is thin and semi formed. Bowel habits are also not okay as I go to rest room a multiple times in a day. Gas makes me feel headache. Also, whenever problems increases I feel pain all around liver. Also, I feel bloated soon after eating. I am concerned could it be cancer of some sort. I was taking to one of the consultants GI in USA, by virtue of my job, and was told that lot of things could be because of low digestive acids which we confuse often with high digesticmve acids. Need help with this situation.