Gastrostomy tube   
A surgical procedure is performed to create an opening in the stomach, which is usually con-nected to the skin of the abdomen with a tube.

Gene   
The biologic unit of heredity that determines the traits a person gets from past generations.

General anesthetic   
A state of unconsciousness produced by anesthetic agents.

Granulocyte   
A type of white blood cell that kills bacteria.

Guaiac test   
A test that checks for hidden blood in the stool.