S2897 Diarrhea in a Patient With Gastrointestinal Tuberculosis

Abstract

INTRODUCTION: Gastrointestinal (GI) tuberculosis (TB) is a rare diagnosis in the United States. Overall, it accounts for approximately 1% to 3% of all TB cases. However, in those who have immigrated from a developing country and are immunosuppressed, extrapulmonary involvement can be more prevalent. We illustrate a case of diarrhea secondary to GI TB. CASE DESCRIPTION/METHODS: A 51-year-old Venezuelan male with end-stage renal disease secondary to autosomal dominant polycystic kidney disease status post deceased donor kidney transplant in 2012 presented with fever, chills, and a three-month history of diarrhea. An increase in bowel movement frequency that was associated with new nocturnal awakening prompted his emergency room visit. He reported no blood or mucus in his stool, no steatorrhea, and no recent travel or exposure to new foods. At his own discretion, he took fewer tablets of mycophenolate mofetil without any significant improvement. There was no recent antibiotic use and no sick contacts. Social history was unremarkable. Vitals showed a temperature of 38.1°C, pulse of 122 bpm, and normotension. A CT scan of the abdomen showed significant terminal ileal thickening. A colonoscopy revealed a patulous ileocecal valve with multiple ulcerations in the terminal ileum (Figure A). Biopsies demonstrated granulomatous ileocolitis with acid-fast bacilli identified on AFB and FITE stains (Figures B, C). Mycobacterium tuberculosis complex was identified from the tissue block by PCR. The patient was treated with a regimen of rifabutin, isoniazid, pyrazinamide, and ethambutol for two months and then with rifabutin and isoniazid for four additional months. The patient experienced substantial improvement in his symptoms once therapy was initiated. DISCUSSION: GI TB can involve the entire GI tract, with the ileocecal region being the most common location. The narrow lumen and relative stasis of the ileocecal region provides an ideal environment for absorption of TB into the lymphatic system with inflammatory response. Long-term inflammation can result in development of fibrotic strictures. Our patient had extensive ulcer development with surrounding hypertrophic reaction but no strictures. Most guidelines recommend a 6-month course of antituberculosis treatment as opposed to 9 months, as there have been similar cure rates with the added benefit of reduced cost and increased adherence. Surgical intervention may be warranted if obstruction or perforation develops.Figure 1.: Patulous ileocecal valve.Figure 2.: Suppurative granulomatous inflammation involving the terminal ileum. Hematoxylin and eosin, 100x.Figure 3.: High power photomicrograph of a granuloma containing acid-fast bacilli. AFB (Ziehl-Neelsen carbol fuschin/methylene blue), 600x.