ABSTRACT.Small bowel permeability was investigated in 87 children with recurrent abdominal pain by measuring the 24‐h urinary excretion of orally administered51Cr‐EDTA. The mean excretion was 3.64%± 1. 49% per 24 h. The difference between the mean urinary excretion in children with recurrent abdominal pain and control children (2.51 %± 0.70 %), was significant (p<0.01, two sample t‐test). The increased small bowel permeability in children with recurrent abdominal pain might indicate an intestinal etiology for the patients' com