I Have IBS, Gastritis, & Esophagitis. I Had A Colonoscopy

I have IBS, Gastritis, & Esophagitis. I had a colonoscopy a year ago, they found nothing wrong. Only thing it showed was my colon is very long. I've had CT Scan. They found out it takes me twice as long to digest my food than a normal person. I take 2 Prilosec every morning, take 1 Bentyl 4 times a day. Take 1 OC Phazym in evening before dinner. I'm lactose intolerant, so I'm very careful of what I eat. But I still have stomach flareups of stomach cramps, loose bowels, & diarrhea quite often. Nothing has stopped this misery.