Talk to Gastroenterologist on Bowel And Stomach Disorders

I am male, 32 from Karachi. I have a problem of stomach and bowel disorders from 2-3 years. My stomach produce a lot of gas and I have to fart 15-20 times a day. Another problem with me is that my stomach gets upset after every 7-10 days and results in loose motion therefore I have to take immodium capsule to control loose motion. I have a history of piles for which I had surgery (HALO/RAR Technique) 6 years ago. Now doctors say that my anal muscles have been disturbed after surgery. Recently, I had colonoscopy and anal manometry done as per advice from doctor (Reports attached). I am unable to understand what is the problem with me. Why my stomach gets upset all the time. Are there any tests required to diagnose this disease. Please guide what tests should I go for to detect the problems with my stomach or intestines. I would be very thankful