Doctors are really focused on things like potassium levels and macrobiotics and chemical and drug reaction issues when 99% of all GI problems are lifestyle caused.
Stop drinking, stop smoking, get right with every family member no matter how dysfuntional they are, eat three sensible meals every day at the same time get 7 hours of uninterrupted sleep and unless you have GI cancer it will all go away.
Cast all your care upon Him; for He cares for you. (1 Peter 5:7)