Mesenteric VeinsPortal VeinMesenteric Vascular OcclusionVeinsPortal SystemIntestine, SmallSplenic VeinIntestinal ObstructionInflammatory Bowel DiseasesFemoral VeinRenal VeinsCapsule EndoscopySaphenous VeinShort Bowel SyndromeSplanchnic CirculationIleal DiseasesIliac VeinIntestinal DiseasesIleumJejunumVaricose VeinsJejunal DiseasesIrritable Bowel SyndromeIntestinal NeoplasmsVenous ThrombosisHepatic VeinsGastrointestinal HemorrhageVisceraIleal NeoplasmsJejunal NeoplasmsHypertension, PortalPulmonary VeinsPancreaticoduodenectomyVena Cava, InferiorIofetamineCrohn DiseaseJugular VeinsMesenteric Artery, SuperiorMesenteric ArteriesTomography, X-Ray ComputedGastrointestinal TransitNorepinephrineAnastomosis, SurgicalIntestinal PerforationLiver CirculationPortasystemic Shunt, SurgicalIntestinal AbsorptionAdrenergic alpha-2 Receptor AntagonistsEsophageal and Gastric VaricesAmphetaminesEndoscopy, GastrointestinalIntestinal MucosaDouble-Balloon EnteroscopyDogsThrombosisCapsule EndoscopesMuscle, Smooth, VascularGastrointestinal MotilityUmbilical VeinsBezoarsBudd-Chiari Syndrome