Assessment of a Radiographic Method for Diagnosis of Intestinal Lactase Deficiency: A Prospective Study

Abstract

A radiographic method for the diagnosis of intestinal lactase deficiency has been evaluated. Twenty-five patients had two small bowel series, 1 with lactose added to the barium and 1 with sucrose added. The films were read independently by 3 radiologists without knowledge of the type of barium utilized. Stool lactose determination was done following the lactose barium study and intestinal biopsies were done on 10 of 13 patients who had an abnormal small bowel study, abnormal stool lactose determination, or both. Roentgenographic diagnosis agreed with intestinal biopsy in 8 cases; the 4 with proven lactase deficiency had abnormal roentgenograms and 4 were negative by both techniques. Two false-positive radiographic studies were recorded; in neither instance were all radiographic features present nor was there unanimous agreement among the radiologists that they were positive. By requiring all 3 radiographic features to be present before making a diagnosis, the roentgenographic method should be useful in detecting previously unrecognized lactase deficiency.