Lactose malabsorption is a common cause of recurrent abdominal pain in childhood (RAP). The diagnosis is often suspected by both the physician and the family from the patient history, and many patients self-restrict dairy products prior to any evaluation. We undertook a prospective study examining the ability of the pediatric gastroenterologist (PGI) to predict the presence of lactose malabsorption in children based on the initial presenting symptoms, dietary history, and exam. In addition, the frequency and appropriateness of altered dairy product intake was determined. A total of 115 patients (mean age 10.9 years, range 4.5-21, 53 male, 62 female) with nonspecific GI complaints(RAP, flatus, diarrhea) were seen and predicted as positive, negative, or indeterminant by the physician, and underwent lactose breath H2 testing. A standard challenge of 2 g/kg up to 50 g with H2 sampling at 30 minute intervals for 4 hours was performed (positive > 20 ppm). Negative tests were confirmed with a lactulose challenge. 63 were positive and 52 negative. Of the positive group, 49% (n=31) were predicted as positive by the PGI with 38% (n=24) predicted negative and 13% (n=8) indeterminate. Of the negative group, 44% (n=23) were predicted positive by the PGI with 46% (n=24) predicted negative and 10% (n=5) indeterminate. 54 of the 115 patients were restricting dairy products at the time of evaluation. Of the 54 patients who were restricting their diets, 30/54 (56%) tested positive while 24/54 (44%) were negative.
Conclusions: 1) Lactose malabsorption in children with non-specific GI complaints cannot be reliably predicted from clinical and dietary history, even by subspecialists. 2) Empiric restriction of dairy products is commonly inappropriately employed in children.
