Ileal pouch morphology and microbiology in ulcerative colitis patients

Ideal pouch created during restorative proctocolectomy is a new gastrointestinal organ--"neorectum". Although it is made from the ileum, it takes over function of the removed rectum. This new function results in significant morphological changes in pouch's mucous membrane, which becomes similar to the large bowel mucosa. The most common pathology of the ileal pouch is its inflammation--pouchitis. One of the suspected causes of pouchitis is bacterial flora disturbance. The aim of the study was to analyze the morphological and microbiological changes in ileal pouches in different time periods after ileostomy closure and to evaluate the influence of certain bacterial strains on the degree of inflammation. The study involved 47 patients who had been treated surgically; they were investigated before and at different stages after ileostomy closure. They underwent repeated rectoscopies with biopsies of pouch mucosa and swabs for microbiological examination. In total 89 rectoscopies were performed, which provided 70 histopathological results according to the Heidelberg Pouchitis Activity Score and 87 microbiological test results. The assessment of the morphology of intestinal pouches showed increased signs of chronic inflammation as the length of time after the closure of a protective ileostomy increased. There was no correlation between the signs of acute inflammation and the length of time after surgery; there were more signs of acute inflammation in cases of pouchitis. The composition of the bacterial flora of intestinal pouches changed as the length of time after ileostomy closure increased, with significant increases in the number of enterobacteriaceae species. The presence of Staphylococcus aureus significantly correlates with a higher degree of chronic inflammation; this bacterium may be a potential infectious factor in pouchitis. Microbiological analysis of intestinal pouch lumen is a useful tool that can be used in routine follow-up assessment of intestinal pouches as well as in diagnosing pouchitis.