I Have Had A Big Gut Since 45 Yearsold, I

I have had a big gut since 45 yearsold, i am 57, am iam thin everywhere else, im 5.8 long legs which are thin, I also have IBS, and just a bad stomach with acid stomach, bloating and gas, i just signed up for weight watchers, and go to excersise classes, i used to go to gym, i had a sonogram on my stomach , and nothing is wrong, some woman asked me when i was due, at class, what si wrong with me