This study reports 70 children suffering from malabsorption and/or carbohydrate intolerance followed for at least twelve months. Mono and dysaccharide overload curves are considered as very valuable tests together with the clinical signs. These must be carefully observed during the tests and after supression of the malabsorbed sugar. Reliability of the overload tests in the follow-up is pointed out. Variations in the normalization time of the curves for each carbohydrate are determined. Finally 90 min. is considered as an advisable end-point for overload tests.