If a 10-day-old kitten is having trouble defecating, it is recommended to first check if the kitten's anus is clear. You can use a thin cotton swab dipped in soap to try.

If the cat's anus is clear but it still isn't defecating, it may be constipated due to a buildup of stool in its intestines. In this case, you can give the cat an enema to relieve the constipation. Additionally, you should adjust the mother cat's diet to make her milk thicker.