The reasons why cats keep vomiting yellow water are as follows:

1. Gastrointestinal problems in cats may be the main reason for cats vomiting yellow water. If your cat has gastroenteritis, a mixture of gastric juice and food chym may be vomited out, forming yellow water.

2. Cats eating inappropriate food or eating too fast may cause indigestion and then vomiting. Yellow water.

3. If the cat accidentally swallows foreign objects or eats spoiled or unhygienic food, it may also cause vomiting of yellow water.