Stomach problem. Please help us out.

My mom is Diabetic since 15 years.She had been taking medicines for over 11 years,but she suddenly started getting stomach aches and severe burning sensation for which she opted Insulin and now it has been 4 years since she is using Insulin.However, the stomach problem is still persisting.She had gone for Endoscopy, but the reports were quite normal except that her bowels are not clear.Often she gets a gripping pain with burning sensation and that leads to breathlessness.The local Doctors adviced her to avoid spicy food and chillies,but it did not work that well.We tried to consult the Doctors about the fact,but they never bothered.I need your help..I want my mom to get as healthy as possible..please help us out..