Background: A deranged mucosal permeability, demonstrated in several studies, has been proposed to play a role in the pathogenesis of Crohn's disease. The possibility of a genetically determined alteration of paracellular transport has been indicated in some investigations. The identification of a group of monozygotic twin pairs concordant and discordant for Crohn's disease, prompted this investigation.
Methods: Intestinal absorption after an oral load of different-sized polyethylene glycols (mol.wt, 458-810) was studied as 6-h urinary recovery. The study groups comprised twins with Crohn's disease (n = 19) and their healthy twin siblings (n = 9), non-twin patients with Crohn's disease (n = 14), and healthy controls (n = 30).
Results: No differences were found in the absorption of polyethylene glycols between the study groups.
Conclusion: The results give no support to the hypothesis of a genetically determined intestinal leakiness in Crohn's disease.