An epidemiologic study of children with failure to thrive is undertaken in Guatemala. Some of these children with ages 1 to 3 years have repeated bouts of diarrhea, but do not improve with dietary supplements. Jejunal biopsies show blunted, atrophic villi with crypt elongation and chronic inflammatory infiltrates. What is the most likely factor contributing to recurrent diarrhea in these children?
Abetalipoproteinemia Bacterial infection Chloride ion channel dysfunction Disaccharidase deficiency