Lactose malabsorption in Israeli children.

Lactose malabsorption during childhood was studied in 110 Jewish children in Israel, using the lactose hydrogen breath test. Sixty-eight subjects (61.8%) were lactose malabsorbers, 41 (60.3%) of whom were lactose-intolerant with symptoms evidenced during or following the tests, whereas 27 (39.7%) were symptom-free (tolerant malabsorbers). In the youngest age-group (4 months to 3 years), no lactose malabsorption was detected, whereas in the higher age-groups the prevalence of lactose malabsorption increased with age. The percentages of lactose malabsorption in the age-groups 3 to 6, 6 to 12 and 12 to 16 years were 56.5, 65.2 and 75.0%, respectively. The percentages of lactose-intolerant subjects also increased in the same age-group, to 26.5, 39.1 and 65.0%. There were no significant differences in lactose malabsorption and tolerance between the various ethnic groups tested. The peak values of breath hydrogen were higher in lactose-intolerant than in lactose-tolerant malabsorbers.