Bloat or not?

[Tipofi]

I have seen other mouse posts on here so I hope I'm not breaking any rules by posting this, although I couldn't find anything that said I couldn't. Please let me know though!

I have been caring for an orphaned wild baby mouse for the last two weeks, and in the last few days I've noticed he has gotten a large tummy. I switched him to electrolyte formula for a few feedings but it didn't seem to change anything. He is a little over two and a half weeks old and usually eats around .6 ml of formula, never over 1. I originally was feeding soy baby formula but switched to kitten formula because he didn't seem to like it. He now goes the entire night without feedings, and during the night I put rice baby cereal mixed with formula, slightly watered down baby food, a tiny piece of bread soaked with formula, and some oats and water that stay in the tank all day. I usually take the first three out because he doesn't want to eat any formula when I leave them in, and I prefer to feed him during the day so I can monitor him better. A pet store employee suggested I use my old hamster food for him to nibble on, but I've seen a lot of people strongly recommend against it, so I am just going to pick up some real mouse feed when I go to town. This is my first time caring for a baby mouse, and I'm 17 currently without a vehicle in the middle of nowhere so it is a little complicated to get supplies. I'm worried that because it's my first time I am not sure how to tell symptoms such as a hard tummy or too little poop. He eats pretty well, however I am a bit worried because he tends to stop and gasp/gape his mouth until I put the syringe back into it, it almost seems like he has no control over doing it. When he does this I just put the syringe back into his mouth to get him to stop then take it away and give him a minute to chill. He also poops a good amount in my opinion, usually he poops without me even having to stimulate him (I still do at the end of every feeding). He does not have diarrhea, his poop pretty much just soft little droppings.

During the first few days I figured everything was okay and maybe he was normal if not just a little chunky. I always massage his tummy pretty good after feeding so I get a good look every time, and I've noticed his tummy start to look a little dark, slightly purple and yellow. He doesn't show obvious discomfort when I massage him or stimulate him to use the bathroom, he likes to groom me/lick my finger while I do it though which I suppose could be self soothing? I've attached an image from this mornings feeding. Sorry for so much disorganization in one post, I'm just a bit tired and worried!