We took the kitten to the vet, the vet said it had lots of feces in the stomach and unable to excrete properly due to the curvature of the spine.
It was given laxatives and pain killers, but after a day and discharged from the vet, the stomach is even much bigger than when we brought the kitten to the vet. The stomach is large for a kitten.
Maybe the laxative and painkillers are not the solution but time is short if it doesn't get resolved the kitten will probably pass away in a few days. The vet did not allow people in the office and only through the guard so we have no idea what its chances are.
The kitten was never able to walk properly. It always limped and struggled and would always end up on its back for the whole day. Lately, the cat never walked anymore and just kept peeing itself so we had to bring the kitten to the vet.