Vasculitis associated with intestinal bypass surgery.

We report two cases in which necrotizing vasculitis with tenosynovitis arthralgia/arthritis syndrome developed after intestinal bypass surgery. Each of these patients had jejunoileostomies, and the excluded segment was placed in an ileal-colonic anastomosis. We speculate that since the attachment of the excluded segment to the large intestine predisposes it to increased bowel overgrowth of bacteria, these bacteria or their debris may have served as antigens for circulating immune complexes, which were detected in both patients by one or more techniques. Patients who have had an end-to-side anastomosis may be less predisposed to the more severe vasculitis syndrome because there is less likelihood of bacterial overgrowth in the bypassed intestinal segment.