PATJ and irritable bowel syndrome: The underlying mechanisms of postinfectious IBS (PI-IBS) pathogenesis, though not clearly understood, are potentially caused by residual inflammation or by alterations in mucosal immunocytes (B and T cells), mast cells, enterochromaffin-like cells, and the intestinal flora [4,6], as well as altered intestinal permeability (decreased expression of the tight junction-associated proteins Zonula occludens-1 (ZO-1) and α-cathenin) [7].