Physiological bases of digestion and absorption of
carbohydrates are reviewed, as a preliminary step, in order to draw a general scheme of its patholophysiology. Clasification of different types of
carbohydrate malabsorption is presented. Various exploration methods are discussed in terms of autors' own experiences. Relationship between a
sugar screening test, faecal
lactic acid contents and a simplified
lactose tolerance test, is described in detail. Systematic diagnoses of these diseases are established. Different clinical pictures are reviewed. It is not yet well defined if a
starch malabsorption can be caused by either a primary or secondary duodenal
amylase deficiency. The clinical forms of congenital
sucrose-
isomaltose intolerance may be more attenuated than its classical form; incertain cases, secondary
sucrose intolerance may also be present due to mucosa anatomic lesions.
Maltose malabsorption has no clinical implications. As compared to other alpha-glycosidades, the
trehalase activity has been not more affected by not using
trehalose in feeding. Primary
congenital lactase deficiency is not frequent, whereas secondary forms as much more usual and appear, in primary
malabsorption syndromes and in the coeliac disease, very often along with clinical tolerance to
lactose. In Spain,
lactose nonabsorbers in 16.5% for adults 11.2% for adolescents and 18.3% for children, meaning, that it is being favored by environmental factors in the latter. The unspecified
sugar malabsorption during the child's first year is still the most frequent cause of
carbohydrate intolerance in children and, although certain progress has been achieved in its diagnosis and
therapy, its pathogenic mechanism is not satisfactorily known yet.