I've gained 15-20 lbs. in the last three months (5'6", currently about 120lbs.). At the start of recovery, my stomach bloated horribly, which is normal of course, and then it seemed like it started to even out a bit. I thought my weight was finally starting to redistribute. Now, in the past week or so -- and now that I'm in a normal weight range -- my stomach suddenly got HUGE again!
Why? I'm not eating any differently. I'm getting plenty of fiber, drink lots of water and watch my salt, but I do not have my period yet. I'm trying to keep a positive outlook about this, but it's so hard! What's worse is that I was feeling so good about my "recovery" body, but not so much at the moment! :(
If you haven't gotten your period yet, your body could be preparing for that. Or, it could simply be that you're consuming more sodium (lots of processed foods tend to have more sodium, like if you're eating a lot of canned foods, cottage cheese, cereals, etc). Or if you've increased the volume of food you're eating (incorporating more fruits and vegetables) your stomach will naturally be larger because it's holding more food. I hope this helped. Congrats on your progress