This study was designed to screen several treatments for their effects on mucosal repair in an established model of piglet rotavirus enteritis. Six ingredients selected to facilitate repair were added to the oral rehydration solution (ORS) and subsequently to the diet: L-glutamine (GLN); rice solids; a soluble fiber (carboxymethylcellulose); nucleotides; polyamines; and fructooligo-saccharides. Rotavirus infection consistently induced a watery diarrhoea lasting 5 to 10 days and produced a jejunal mucosal lesion which was maximal at 3 days, post-inoculation (manifested by a reduction of villus surface area to 30% to 50% of normal). By 7 to 10 day post-inoculation, the villus surface area returned to 50% to 80% of normal. None of the supplemental ingredients added to the ORS had a significant effect in either shortening the clinical illness or in stimulating recovery of the affected mucosa. It is concluded that several types of "Super ORS" are ineffective in enhancing repair in viral enteritis in neonatal colostrum-deprived piglets. These results do not rule out beneficial effects of the additives tested in subjects with more extensive intestinal damage, in those who receive breast milk, or in those with bacterial enteritis.