I had the same problem. My stomach would be so distended by the end of the afternoon that I would unzip my pants on the ride home in my car.
I am not a heavy person. I am 5"4 and weigh about 120 lbs. I exercise daily. I looked pregnant and was so incredibly uncomfortable.
I had bloating, gas, stomach rumbling, etc.
It seemed like overnight my abdominal muscles quit on me and my midsection looks flabby. I have not gained any weight so that is not the reason.
I went for colon hydrotherapy cleansing and also did a parasitic cleanse, and a coffee enema ( not all at once, over a period of a few weeks). It worked miracles. I was also on azith and cefdinir at the same time.
It is a relief to know that I am not alone in this. Not that I want company........just makes you feel that you are not imagining these things.
On the down side, it is all coming back. However, I did stop the abx so that may be the reason.