Why does my kittens have a bad attack of diarrhoea ?

Question
I have 4 kittens about 7 weeks old. I fed them wet cat food and sometimes cooked fish. But it seems like 3 of the kitties are suffering from diarrhoea. Fortunately none of them lost appetite due to this. But then, I saw worms in their litter. How can I treat them as in for food and medication ?  

Answer
try starting the kittens on dry kitten food instead of wet food and fish. They are old enough to start eating dry food, plus wet food can cause dirrhoea. And the worms are due to fleas, you can go to the store like wal-mart and they will have medicated baths to get rid of fleas and medicine to get rid of the worms all in the pet section. When you browse through the products, make sure to find the right product for the kittens age, since they are still young and sensitive to certain products.