Your snake has a VERY serious life threatening situation on your hands. And if you follow these simple steps I have suggested to many other folks in the past, your snake will very likely pull through if it is not too late already and go on to thrive like there's no tomorrow.
But you need to follow these simple steps to the very LETTER for it to work if you do not want to make it worse with more regurgitations. The tiny snake's body simply CANNOT afford any more regurges or it will be dead soon.
I have told people about this when their snakes were regurgitating, very imaciated, and literally on deaths doorstep. These people did exactly as I said to the letter and their snakes bounced back and were later pounding meals and put on three times their weight in no time after doing these very important things here. DO NOT attempt to feed it ANYTHING until you get it treated first, or it will simply regurge all over again!
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I strongly suspect the problem to be bad microbial pathogens in the gut. If the snake was able to earlier get from an ambient cool temp of the mid 70's (comfortable human dwelling temps) to a warm side on ONE SIDE ONLY of it's small enclosure of around 82 to 86 and was still regurging, I suspect it likely has some intestinal microbial pathogens. This can happen from fouled water, etc..
A snake has to be able to seek slightly warmer temps when it needs to to be able to properly digest it's meals so the prey item doesn't putrify(rot) instead.
First,….DO NOT attempt to feed it more meals until it has been looked at, I strongly suspect it has some nasty intestinal bacteria from the putrid previous meals. I would imagine a two-dose regimen of Flagyl(metronidazole) administered by a vet could EASILY be all that is needed here. This treatment will kill the bad protozoa/pathogens as WELL as the GOOD bacteria that is needed for proper digestion, so STOP offering it any food until the snake has been looked at and helped. Feeding at this point will only lead to more regurges and a DEFINITE downward spiral that could easily end up killing it in short order. Offering food at this point is the WORST thing you could possibly do right now until you tackle the intestinal problem at the source.
Hopefully the vet will already know the proper course of action as I am about to explain, but MANY vets don't know diddly squat about reptile medicine whatsoever. The snake should get a dose of of Flagyl (Metronidazole) at the rate of 50 mg./per kg. of body weight given orally, and another follow-up dose 10 to 14 days later. NO FOOD should be offered until at LEAST a good week or so AFTER the last dose so the snake can replenish it's vital stomach acids, electrolytes, enzymes and gut flora before being fed again. And when it IS fed again, they should be very small meals for a while to make absolutely certain they stay down and are digested properly, you cannot afford for this to happen any more whatsoever.
After several VERY small meals, you could then GRADUALLY increase the size back to the size prey it was normally eating, just make sure you don't offer large meals after the dosing of the medication, Sometimes snakes develop this from fouled water too, so who knows, but I would bet a dollar to a donut some Flagyl at the proper dosing will take care of this. Flagyl is very reptile friendly too!
If it does not hold down it's next VERY tiny meal when given in two weeks, the snake will very likely be dead without the proper dosing of the Flagyl. This stuff works wonders when applied in the correct circumstances, and this could EASILY be one of them. I have administered Flagyl to snakes that have had this problem before in the past, and it works like magic!! Several years ago, I had a 300 gram Honduran start regurging meals seemingly out of nowhere, and did it again no matter how small the mice were. This was indeed time for immediate action to be taken. After I gave it the proper dosing of Flagyl (50 mg/per kg body weight),....BAM!, problem gone FOREVER! and it is now a huge 6 year old adult breeder female now that eats like no tomorrow every single time ever since I gave her the necessary medication to put her back on track.
hope the little snake gets better, because it's life all depends on what you do here,...it's really just as simple as that.
good luck!, ~Doug