Fractured colon: an endoscopically distinctive lesion associated with colonic perforation following colonoscopy in patients with collagenous colitis.

BACKGROUND

Collagenous colitis is characterized by collagen deposition in the superficial colonic mucosa, beneath the surface epithelium, resulting in chronic nonbloody diarrhea of variable severity. The mucosa generally appears endoscopically normal.

METHODS

We report the occurrence of distinctive linear mucosal tears, unassociated with trauma, in 4 patients during diagnostic colonoscopy. The patients' tissue specimens were examined histologically, and clinical courses were recorded.

OBSERVATIONS

Recognition of linear "fractures" was followed in 3 patients by colonic perforation. One patient required colectomy. Severe collagenous colitis was present in all. The resection specimen contained shallow linear ulcers overlying fibrotic submucosa, with pneumatosis and acute peritonitis.

CONCLUSIONS

We theorize that the stiffness of the colon in areas of collagenous colitis with submucosal fibrosis makes it susceptible to linear "fractures" during colonoscopic air insufflation with subsequent transmural air dissection. We urge extreme caution if this lesion is recognized at colonoscopy and recommend aborting the examination and obtaining plain radiographs to detect free intraperitoneal air.