I Have Stomach Problem For The Last About 4 Years.

I have stomach problem for the last about 4 years. Highly bloated, pain on both sides of stomach below the ribs, nausea feeling but never vomited, pain in back, shoulders, head and legs means all over the body, constipated stool formation is very thin as if the passage has narrowed, burning sensation in stomach. when i take zinetac (Ranitidine hydrochloride IP 168 mg, then i get relief. but if i start taking this pill on daily basis continuously for about a week, it has its own side effects like pain in whole body, stomach bloating and pain again starts while taking pill. My endoscopy and colonoscopy are normal, blood work for helicobacter pylori is negative. please guide me what could be the problem and its treatment.