The Collaborative International Dictionary of English v.0.48:

Intestinal \In*tes"ti*nal\, a. [Cf. F. intestinal.]
   Of or pertaining to the intestines of an animal; as, the
   intestinal tube; intestinal digestion; intestinal enzymes.
   [1913 Webster]

   Intestinal canal. Same as Intestine, n.

   Intestinal worm (Zool.), any species of helminth living in
      the intestinal canal of any animal. The species are
      numerous.
      [1913 Webster]

WordNet (r) 3.0 (2006):

intestinal
    adj 1: of or relating to or inside the intestines; "intestinal
           disease" [syn: intestinal, enteric, enteral]

Moby Thesaurus II by Grady Ward, 1.0:

18 Moby Thesaurus words for "intestinal":
   abdominal, anal, appendical, cardiac, cecal, colic, colonic,
   coronary, duodenal, enteric, gastric, ileac, jejunal, mesogastric,
   pyloric, rectal, splanchnic, visceral