ABSTRACT. We examined the effects of refeeding during an acute bacterial enteritis on small intestinal repair in infant rabbits subjected to protein-energy malnutrition and in noninfected and infected dietary controls. Malnutrition was induced by litter expansion at 7 d of age. Randomly selected litters from both dietary groups were infected on d 17 with Yersinia enterocolotica. Inflammation and intestinal damage were observed in the jejunum and ileum at the "acute stage" of infection in 23-d-old animals from both dietary groups, as evidenced by an inflammatory infiltrate, blunted villi, and reduced disaccharidase activities. In addition, ileal glucose-stimulated Na+ absorption was depressed. On d 24, a 7-d period of ad libitum refeeding of breast milk and rabbit feed was initiated in randomly selected litters of infected-malnourished animals and all dietary controls. Mucosal repair was nearly complete at 31 d of age in infected dietary controls and in the infectedmalnourished animals that were refed, as demonstrated by the recovery of segmental mucosal mass and ileal glucosestimulated Na+ transport in association with the resolution of inflammation and diarrhea. Only mucosal disaccharidase activities remain depressed. In contrast, in 31-d-old infected-malnourished animals subjected to ongoing nutrient deprivation, severe intestinal damage persisted as evidenced by increased mortality, ongoing intestinal inflammation, mucosal hypoplasia, depressed disaccharidase activities, and reduced glucose-stimulated Na+ transport. We conclude that a refeeding regimen introduced during an acute bacterial enteritis is well tolerated and promotes recovery of intestinal mass, structure, and function in malnourished infant rabbits and dietary controls.