Intestinal Spirochetosis: An Obscure Cause of Lower Gastrointestinal Bleeding

Abstract

Intestinal Spirochetosis is a condition marked by anaerobic spirochetes adherence and colonization of the luminal surface of colonic epithelium with occasional penetration into the epithelium. Most cases are found incidentally on pathological evaluation of colonic biopsies taken during diagnostic or therapeutic colonoscopies. However, whether the colonization of the intestinal mucosa can be attributed to clinical symptoms is a matter of debate. Here we present a case of intermittent hematochezia due to invasion of the colonic mucosa by intestinal spirochetes. A 27 year old male with no medical history presented with four days of atypical chest pain and syncope the day prior to presentation. He also reported watery diarrhea and intermittent hematochezia for the past two weeks. A complete cardiovascular and neurologic workup was unremarkable. After a spontaneous episode of painless hematochezia he was found to have a decrease in Hgb from 14 g/dl to 10 g/dl. CRP was 6.5 and ESR was 60. All stool studies, including Clostridium difficile toxin were negative. Coagulation studies were within normal limits. Physical exam was unremarkable except for guaiac positive stool. Colonoscopy was performed, revealing mild erythematous mucosa of the terminal ileum, and a localized area of severely congested, erythematous and inflamed mucosa in the rectum. Random biopsies were taken. Intestinal spirochetes were found in biopsies of the ascending colon, transverse colon, descending colon, sigmoid colon, rectum, and cecum. Terminal ileum and rectum biopsies showed nonspecific inflammatory changes. The overwhelming spirochete invasion suggested these changes were secondary to the infectious process. Screening for all sexually transmitted diseases was negative. He was treated with metronidazole and improvement in symptoms was reported. This case demonstrates that invasive IS may develop in healthy individuals. Although many cases of asymptomatic IS have been described, cases leading to severe gastrointestinal symptoms are rare. No current methods exist to prove a direct relationship between histologic findings of IS and active disease thus leaving IS as the diagnosis of exclusion. Diagnosis requires random colonic biopsies followed by direct visualization via histologic staining, and may be confirmed by fluorescence in situ hybridization. Treatment of IS is controversial and ultimately should be dictated by the presence of symptoms, after all other etiologies have been ruled out.Figure: Erythematous Colonic Mucosa.Figure: False Brush Border Intestinal Colonization of Spirochetes along the colonic epithelium.