IgE plasmocytes were looked for in small bowel biopsy tissue of 24 children suspected of having small bowel injury. Immunoperoxidase techniques were applied making use of both conventional and monoclonal IgE antibodies. IgE positive cells were counted and results expressed as the number of IgE positive cells per square mm of lamina propria. An increased number of IgE positive cells was only found in 3 children with cow's milk allergy (mean 143 cells/mm2), while all other patients showed very low numbers of IgE positive cells (mean: 4 cells/mm2). A normal number of IgE positive cells was found in 2 patients with cow's milk allergy on a cow's milk free diet.