Wordnet 3.0
ADJECTIVE (1)
1. 
 of or relating to the stomach and intestines; 
- Example: "a gastrointestinal disorder"[syn: gastrointestinal, GI]
The Collaborative International Dictionary of English v.0.48:
Gastrointestinal \Gas`tro*in*tes"ti*nal\, a. [Gastro- +
   -intestinal.] (Anat. & Med.)
   Of or pertaining to the stomach and intestines;
   gastroenteric.
   [1913 Webster]
WordNet (r) 3.0 (2006):
gastrointestinal
    adj 1: of or relating to the stomach and intestines; "a
           gastrointestinal disorder" [syn: gastrointestinal,
           GI]