My kittens have diarrhea after eating adult cat food. What to do?

Congrats on your kittens but I'm sorry they are sick! It may be the change of diet that is causing this foul stools, and I would take them off that food. An adult cat food is not appropriate for kittens. They need higher amounts of calcium, protein, and calories than adult cats to grow properly, so they need to be on a kitten food. They may be eating voraciously because they are so hungry and their nutritional needs are not being met with the adult cat food. Take them off the adult cat food, and buy kitten food. Start them on a bland diet of boiled white meat chicken (no bones) in small amounts to see if that helps settle their stomach and clears up the diarrhea, and after two days on the bland diet, start adding in the kitten food. You can mix the boiled chicken with the dry or wet food. Over the next week, decrease the amount of chicken and increase the amount of kitten food until they are eating the kitten food only. If the bland diet does not help clear up the diarrhea, they will need to see a vet. Good luck, I hope this helps!