They can live inside the gastrointestinal tract or, the case of roundworms, in the lymphatic system.
The drug is approved in Canada, but only for its gastrointestinal use.
After all, what says Christmas more than obligations, gastrointestinal distress, and insane dining companions?
gastrointestinal gas·tro·in·tes·ti·nal (gās'trō-ĭn-těs'tə-nəl)
Abbr. GI Relating to the stomach and the intestines.