How Can Severe Abdominal Bloating After A Stomach Surgery Be Treated?

I had a stomach bypass surgery in 2002 & have a constant problem of gas, lots of it!! Especially after eating, but also during almost the entire day & during my sleeping hours. I have been seeing a gastroenterologist for the last 3-4 yrs. Have tried over the counter remedies as well as Creon or Pancrease but these rx ,s cause me more bloating than I already have; my ? Is I have no gall bladder & I was wondering if cholestyramine powder might work to stem they circumstances of gas,bloating, & diarhea. I am certainly at my wits end & so embarrassed to go out in public because of the odor, & my family has certainly had enough in the home as well. At present I take several rx ,s. The xarelto, spironolactone, gen. lasix, gen. Effexor, gabapenton, klor-con,metoprolol. Could you recommend anything?