The intestinal lesions caused by ischemia and reperfusion may lead to grave sequelae. To study the efficacy of adenosine triphosphate magnesium chloride (ATP-MgCl₂) and allopurinol (ALLO) in protecting the small bowel from ischemia, rabbits in two groups, 1 (n = 7) and 2 (n = 7), were pretreated with either 1 ml saline or ATP-MgCl₂ just prior to intestinal ischemia and reperfusion. Group 3 (n = 7) animals recieved enteral ALLO daily for 3 days before the experiment. Using Oldham and Thompson's grading system, histologic specimens were evaluated blindly for evidence of ischemic-reperfusion injury. The histologic injury scores in group 2 were significantly lower than those in groups 1 and 3 (P <0.05 and="" 0.02,="" respectively)="" after="" 2="" h="" of="" ischemia.="" following="" 30="" min="" of="" reperfusion,="" histologic="" injury="" scores="" rose="" significantly="" in="" group="" 1="">P <0.05), decreased="" in="" group="" 2="">P <0.005), and="" showed="" no="" significant="" changes="" in="" group="" 3="">P >0.50). We conclude that: (1) pretreatment with ALLO can prevent reperfusion injury of the small intestine; and (2) ATP-MgCl₂ administration can reduce 2-h ischemic intestinal damage, reverse reperfusion-induced cellular injury, and improve the recovery of ischemic bowel during the reperfusion phase.