AIM: To investigate the effects of ketamine anesthesia on the motility alterations and tissue injury caused by ischemia/reperfusion in rats. METHODS: Thirty male Wistar rats weighing 200-250 g were used. Ischemia was induced by ob-structing blood flow in 25% of the total small intesti-nal length (ileum) with a vascular clamp for 45 min, after which either 60 min or 24 h of reperfusion was allowed. Rats were either anesthetized with pento-barbital sodium (50 mg/kg) or ketamine (100 mg/kg). Control groups received sham surgery. After 60 min of reperfusion, the intestine was examined for mor-phological alterations, and after 24 h intestinal basic electrical rhythm (BER) frequency was calculated, and intestinal transit determined in all groups. RESULTS: The intestinal mucosa in rats that were anesthetized with ketamine showed moderate altera-tions such as epithelial lifting, while ulceration and hemorrhage was observed in rats that received pento-barbital sodium after 60 min of reperfusion. Quantita-tive analysis of structural damage using the Chiu scaleshowed significantly less injury in rats that received ketamine than in rats that did not (2.35 ± 1.14 vs 4.58 ± 0.50, P < 0.0001). The distance traveled by a mark-er, expressed as percentage of total intestinal length, in rats that received pentobarbital sodium was 20% ± 2% in comparison with 25.9% ± 1.64% in rats that re-ceived ketamine (P = 0.017). BER was not statistically different between groups. CONCLUSION: Our results show that ketamine anesthesia is associated with diminished intestinal injury and abolishes the intestinal transit delay induced by ischemia/reperfusion. A: To investigate the effects of ketamine anesthesia on the motility alterations and tissue injury caused by ischemia / reperfusion in rats. METHODS: Thirty male Wistar rats weighing 200-250 g were used. Ischemia was induced by ob- structing blood flow in 25% of the total small intesti-nal length (ileum) with a vascular clamp for 45 min, after either either 60 min or 24 h of reperfusion was allowed. The rats were either anesthetized with pento-barbital sodium (50 mg / kg) or ketamine 100 mg / kg) Control groups received sham surgery. After 60 min of reperfusion, the intestine was examined for mor-phological alterations, and after 24 h intestinal basic electrical rhythm (BER) frequency was calculated, and intestinal transit determined in all groups RESULTS: The intestinal mucosa in rats that were anesthetized with ketamine showed moderate altera-tions such as epithelial lifting, while ulceration and hemorrhage was observed in rats that received pento- barbital sodium after 60 min of reperfusion . Quantita-tive analysis of structural damage using the Chiu scales showed significantly less less injury in rats that received ketamine than in rats that did not (2.35 ± 1.14 vs 4.58 ± 0.50, P <0.0001). The distance traveled by a mark-er, expressed as percentage of total intestinal length, in rats that received pentobarbital sodium was 20% ± 2% in comparison with 25.9% ± 1.64% in rats that re-ceived ketamine (P = 0.017). BER was not statistically different between groups. CONCLUSION: Our results show that ketamine anesthesia is associated with diminished intestinal injury and abolishes the intestinal transit delay induced by ischemia / reperfusion.