Absorption of carbon 13-labeled rice in milk by infants during acute gastroenteritis. To determine whether rice cereal could be used to complement a cow milk-based diet in the nutritional management of infants with acute diarrhea, we assessed its digestion and absorption in eight affected male infants, 69 to 131 days of age. They received cow milk formula with 5.4% lactose (diluted 1:1 with water and precooked rice cereal) 5 to 22 hours after admission and rehydration. The first feeding consisted of milk diluted with carbon 13-enriched rice cereal. A 48-hour fecal collection and balance study was performed. Rice cereal was reasonably well absorbed (84.0% to 95.8%) by seven of the eight infants. The study was repeated in seven of the infants after they had recovered. Our results indicated that rice cereal is well absorbed by young infants with acute diarrhea and that it is an adequate nutrient supplement for this patient population. 