Get an endoscopy if you think your WLS has failed
If you had an RNY, the best way to find out if the surgery has failed is to get an endoscopy. It can be ordered by your PCP or surgeon. If you are eating like a food addict, the reason for your weight problem may be more complicated. But, if you are following the rules as well as you can and are still gaining weight, then it's best to get scoped.
Bob is right. Or it could be an enlarged stoma or both. My DH wasn't happy about my wanting a revision until he saw the results from my endoscopy and upper GI, which proved the mechanical failure of my previous RNY. I had a revision to DS in Aug and am doing great and know the weight will stay off once I lose it all.