A viral etiology has been proposed for the chronic inflammatory bowel disease, Crohn's disease, or regional enteritis, and the isolation of a reovirus-like viral agent with antigenic relatedness to the Nebraska Calf Diarrhea Rotavirus from tissues of patients with Crohn's disease had been reported. The overall objective of this research plan is to examine the disease rotavirus association using both highly sensitive immunocytochemical techniques and the biochemical technique of nucleic acid hybirdization employing the simian rotavirus SAll to prepare crosss reacting probes.