There are several reasons why a cat might have feces stuck to its rear end, such as indigestion, intestinal problems, or anal gland issues. To address this, you can try the following steps:

1. Cleaning: Bathe your cat regularly and clean its rear end with warm water. You can use pet-specific shampoo to help with cleaning.
2. Trim fur: If your cat has long fur, consider trimming the fur around its anus, which can help reduce the amount of feces stuck to its body.
3. Dietary management: Ensure your cat has a healthy diet and avoid excessive intake of oil and sugar, as these can lead to sticky feces.
4. Veterinary consultation: If the above methods fail to resolve the issue, it is recommended to take your cat to a veterinarian as soon as possible, as professional medical intervention may be necessary to resolve the problem.