As consumption of dietary fructose and sorbitol increases, the association between consumption of these sugars and gastrointestinal symptoms has been recognized. As a result, studies of fructose and sorbitol absorption and malabsorption have emerged with investigations relying largely on the use of breath hydrogen (H2) measurements. Since these sugars are prevalent in fruit juices, a major dietary staple in the first 5 years of life, an understanding of fructose and sorbitol absorption is particularly important to pediatric health care providers. This review examines fructose and sorbitol absorption in humans, reviewing as well the breath H2 method upon which studies of fructose and sorbitol absorption largely depend.