Early diagnosis of a diverticular colovaginal fistula with colposcopy. A case report.

Seventy cases of colovaginal fistula complicating diverticular disease are documented in the literature. Predisposing factors are advanced age and previous hysterectomy. We diagnosed a case early on with careful colposcopic observation of the volcanic ejection of pus from multiple sites in the vaginal apex; we propose naming that phenomenon the "Io" sign after the most eruptive celestial body known. We also documented the association of a coloovarian fistula, ureteral obstruction and endometriosis with this disease process. Considering the expected growth in the geriatric population and the frequency of hysterectomy, clinicians should familiarize themselves with this life-threatening illness.