Gastrointestinal is an adjective meaning of or pertaining to the stomach and intestines. A tract is a collection of related anatomic structures or a series of connected body organs.
You can obtain mother's milk replacer for young kittens at many of the pet stores in the area. When the kittens are 8 weeks or older, they no longer need the milk but may enjoy it anyway. Milk that has been specially processed for cats to consume safely is available from many local groceries. Water. Keep clean, fresh water available to your kitten at all times.
1 Most kittens can handle a diet of solids by seven weeks of age.  A kitten aged between six to 10 weeks old needs to be fed six to eight meals a day, while a kitten aged 10 weeks to six or seven months needs four meals a day and a kitten up to nine months needs three meals a day.