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.
Nutrition and weaning. If at all possible, get the kittens to nurse from the mother in the first 12 hours to allow for ingestion of colostrum. Kittens are only able to absorb the antibodies from the colostrum for the first 24 hours of life.