If necessary, if the stool is too dry, you can drink a little honey to reduce the burden of stool.
The case you mentioned, "After pulling, the anus turned out, red, like a little bloodshot, and there was only a little yellow liquid on the paper, and pp didn't stink." So does my cat. As long as the spirit is good, eating and drinking is basically no problem. . .
There is also the problem that your stomach is big but thin. It seems that cats are thinner when they are 3, 4, 5 and 6 months old, and they can't look symmetrical until they are about one year old.
So is my cat. If you eat too much, your stomach looks bigger. No problem. . If it is an adult cat, it is thin but only has a big belly, then there is a problem.
Don't worry, the kitten looks healthy on the whole.