Hi I Am A 58 Year Old Male Who Has

hi I am a 58 year old male who has been dealing with IBS for about 10 yrs now I am 5'11" and weigh about 197 lbs. I excise 4-5 times a week which includes some running, weight training and ab training daily but still have an extended stomach. My question, could excessive cortisol levels be the cause of the IBS and the extended stomach and any suggestions on how to deal with it . Have seen 3 different GI doctors with whole battery of tests. Any suggestions?