Hi,thanks for query.You might have acid peptic disease
,which can lead to all this problems and still all the reports are normal.Another possibility is Irritable bowel syndrome
,in this again all the test are normal and you can frequent abdominal pain
with off and on diarrhea
.This has got strong association with your mental state,means any major alteration in mood can increase the problem.The treatment is largely symptomatic and relaxation technique for stress.bye.