New To Kittening! Need Advice.

Hello everyone, I am new around here and have learned so much from sifting through your boards; I got a couple of kittens from work some days ago. I work in wildlife rehab and someone brought them to us as every rescue/ foster was overrun with kittens and she didn’t want them put down at a shelter. They were only a couple days old; I was previously a vet tech at a cat specialty hospital so I tossed my name into the ring to take them. My name ended up being the only name. They were dehydrated and chilled so I gave them each a couple cc’s of SQ fluids and got them warmed up slowly. Took them home and they got off to a rough start. They refused any of the 50 nipples I offered no matter the milk inside so I settled on KMR and a good of fashioned tube feeding around the clock. After getting some food in them and a couple long days they eventually took a nipple and are now eating like little piggies.

My real concern is their bathroom habits. They’re about 2 weeks old at this point active when they’re awake for food and otherwise asleep. Once they were rehydrated at a couple days old everything was going fine. Pees and poops were normal for tiny kittens. I understand canned formula can bind them up so every time things started getting firm I’d add a little extra LRS to their formula and everything went back to normal. The issue went away within a couple of days and nothing has been a problem since. They’re gaining adequate weight and feeding great (about 60-65cc per day at 7.5oz). But for the last day and a half both have had back and forth bowel movements, by that I mean the last couple of days they’ll be bound up, a little runny then normal. Every poop from them is different. Once their old enough to deworm it’ll get done and if it gets worse they will be going to the vet. I’m just wondering is this kind of normal for bottle babies? Like I said, their movements aren’t so far from normal I’m worried right yet; when they push, poop comes out and if it’s runnyish it doesn’t just come out with no effort and they each had one bm that was a little green but I read that it can happen if their constipated and it’s from bile buildup. They are adequately hydrated and are fed around every 3-4 hours from 5am to 11pm. Is there something I could be doing wrong or does this seem to be something they go through as they grow? Their bellies are round but soft and get smaller after burping and stimulating; nothing gigantic or terrible looking and they are on bene-bac for their tummies.

Any help or advice is greatly appreciated!