HISTOLOGIC AND MICROBIOLOGIC FEATURES OF BIOPSY SAMPLES FROM PATIENTSWITH NORMAL AND INFLAMED POUCHES

PURPOSE: This study was undertaken to assess the electron microscopic and microbiologic findings in tissue biopsy samples from patients with pouchitis and to compare them with findings in patients with normal p ouches, conventional ileostomies, and normal ileum. METHODS: Tissue sa mples were obtained from 78 patients: 23 patients with normal pouches endoscopically and histologically (Group 1), 12 patients with endoscop ic and histologic evidence of inflammation (pouchitis) (Group 2), 14 p atients who had either endoscopic or histologic evidence of inflammati on but not both (Group 3), 20 patients with conventional ileostomies ( Group 4), and 9 patients without ileostomies from whom biopsy samples of normal ileum were obtained (Group 5). RESULTS: The mean total aerob ic facultative counts in the biopsy samples from the pouchitis patient s were significantly higher when compared with biopsy samples from Gro ups 4 and 5 (P < 0.05). There were no significant differences in the m ean anaerobic counts among the five groups. Positive cultures were obt ained in 90 percent of patients with pouches compared with 69 percent of patients with conventional ileostomies or normal ileum (P < 0.05). Intramural bacteria were observed on electron microscopy in biopsy spe cimens of 47 percent patients with pouches compared with 14 percent of patients with conventional ileostomies or normal ileum (P < 0.05). Ho wever, the proportion of patients with positive cultures or intramural bacteria was not increased in the pouchitis group compared with the n ormal pouch group. CONCLUSION: These data suggest that intramural aero bic facultative bacterial counts are elevated in patients with pouchit is and may play a role in the pathogenesis of pouchitis.