IleumGuinea PigsMyenteric PlexusIleal DiseasesMuscle, SmoothIleitisIntestine, SmallIntestinal MucosaMuscle ContractionIleal NeoplasmsIntestinal AbsorptionIntestinesColonGastrointestinal MotilityDuodenumDiphenylacetic AcidsIleocecal ValveAtropineAcetylcholineCecumPeristalsisSwineGastrointestinal Contents