Axolotl pooped undigested worms?

Hey guys, this is my first post so I hope I do this right!
Today I bought my axolotl nightcrawlers after not feeding him for two days because we ran out. He refused to eat the backup bloodworms I keep for emergencies so instead he waited for me to get him his earthworms. Anyway, after feeding him one whole earthworm (chopped into like 4-5 medium size bits) he became stressed and curled his tail. I noticed his water had reached almost 70 degrees so I threw in some frozen water bottles and brought it down to 62 degrees. This seemed to help and he was back to normal. A few hours later I noticed that he was in one corner of the tank and wasn't moving or even acknowledging my presence. He was just sitting there & flapping his gills every couple of seconds so I figured he was trying to poop. I walked away & came back maybe two hours later & he had pooped a little but, in a corner, there was the pile of worms I had fed him, completely undigested. I've never seen this before so I'm pretty concerned. I have no idea if he vomited them up because I wasn't watching him when it happened. I wish I had taken photos but I immediately wanted to take them out the tank so as to not spike the ammonia. His water levels are perfect - 7.6 pH, 0 Ammonia, 0 Nitrite, and between 20-40 ppm of Nitrate. He seems to be back to normal and is actually begging me for more food. Has this happened to anyone else?? He isn't curling his tail or his gills so I'm under the impression that he is ok now but I don't know what caused that weird poop / possible vomit. The photos attached are of him right now and if you look closely it looks as if he's not done pooping yet, however nothing yet. Any help would be greatly appreciated! Sorry for the long post, just didn't want to miss any details!

I have had axolotls spit up worms sometimes, I don’t know exactly why they do it but it never seems to bother them. As long as he’s eating SOMETHING I wouldn’t worry. If he’s not eating for a long period of time then I would worry.
Also I know there’s a huge debate about nitrates and what levels are considered good, but I have worked in fish stores for the past three years and I can tell you that from my experience, my customers start having problems when their nitrate levels are at or over 40. If you’re doing weekly 25% water changes and siphoning properly (getting under decorations and getting deep into the sand bed) generally your nitrates will sit at 5-10 ppm, which is a much healthier level. That’s probably got nothing to do with him spitting up the worms, it’s just a little tidbit of advice that I have from my experience working in fish stores.
Your little dude is beautiful btw!

Ok well that’s a big relief, THANK YOU. And I’ll definitely do a water change, I’ve always been a little confused about what level of nitrates are good for them because I’ve gotten a myriad of answers but I’ll definitely work on bringing it down! Thanks for the compliment, we appreciate it!