I was also experiencing extreme pain in my stomach, horrible gastric, stomach tumble, etc. To express in details it was like heat from inside causing to dry mouth and heat on my tongue for long time. Extreme pain in the stomach area feeling like having a fire inside of me. I experienced whole my body become literally red. I couldn't really find any answer from west science to solve this disorder until I came to India and got introduced to Ayurveda. Ayurveda is an ancient indian science which has very different perspective towards west.
Based on Ayurveda every person has a different constitution, Wind, fire and earth. If we like to have a healthy life style we have to keep the all 3 elements balanced in our body. When we have the 3 elements balanced we feel happy and joyful. This science is very simple but has a depth in understanding nature out and in.
I am Pitta person, meaning my fire is overtaking on the other two elements thats I was feeling so much heat and dry mouth. I should cool myself with cold nature food to keep the balance and harmony.
Zucchini, cabbage, white rice, Broccoli, Potato, Coriander (seeds and herb) , Cocao, Coffee, Okra, Banna, Apple, mango, Coconut, Pomegranate etc. are having cooling effect on the body and should be consumed by Pitta (Fire) people.
I should take very little or highly avoid following foods having fire element in summer time:
Tomato (oh I god i love them), dried fruits and nuts, garlic, onion, Spinach, Spirulina, or any food that has a lot of Iron in it. Highly avoid sour and salty food in summer.
The main basic is to recognise which food is good for Pitta person is by its taste. Any food that is sweet, Astringent and bitter is good for cooling the pitta people.
If you like to figure out exactly which elements are dominant in your body, please take online test to determine yours:
https://www.banyanbotanicals.com/info/prakriti-quiz
Please read below article of conscious food combining to avoid indigestion which causes gas in intestine:
https://www.banyanbotanicals.com/info/ayurvedic-living/living-ayurveda/diet/ayurvedic-food-combining/
If you like to change your perspective towards health and life in general I highly recommend you to read few books on this topic written by Vasant Lad and David Frawley. “Ayurveda: The Science of Self-healing : a Practical Guide” is one of the most popular books.
I'm really sorry that you are suffering. I'm not a doctor and I know next to nothing about this stuff but I'm learning through my own illness. Your symptoms could be SO many things including sludge or microscopic stones in the CBD, Post-Cholecystectomy Syndrome, Sphincter of Oddi Dysfunction, Small Bowel Bacterial Overgrowth, pancreatitis, etc. or combinations of these things.
Web groups are a fantastic resource. Search yahoo! groups for "Sphincter", you will find quite a few groups. Both Maddi's and Michele's are worth joining. There is a lot of great information there that might help you.
The Doc that just released you, is he a Surgeon or a Gastroenterologist?
All the best,
Sam