AIM:To investigate the interstitial cells of Cajal(ICC) number using a new rat model.METHODS:Sprague-Dawley rats were assigned to two groups.The first group received gavage with Campylobacter jejuni(C.jejuni) 81-176.The second group was gavaged with placebo.Three months after clearance of Campylobacter from the stool,precise segments of duodenum,jejunum,and ileum were ligated in self-contained loops of bowel that were preserved in anaerobic bags.Deep muscular plexus ICC(DMP-ICC) were quantified by two blinded readers assessing the tissue in a random,coded order.The number of ICC per villus was compared among controls,Campylobacter recovered rats without small intestinal bacterial overgrowth(SIBO),and Campylobacter recovered rats with SIBO.RESULTS:Three months after recovery,27% of rats gavaged with C.jejuni had SIBO.The rats with SIBO had a lower number of DMP-ICC than controls in the jejunum and ileum.Additionally there appeared to be a density threshold of 0.12 DMP-ICC/villus that was associated with SIBO.If ileal density of DMP-ICC was < 0.12 ICC/villus,54% of rats had SIBO compared to 9% among ileal sections with > 0.12(P<0.05).If the density of ICC was < 0.12 DMP-ICC/villus in more than one location of the bowel,88% of these had SIBO compared to 6% in those who did not(P<0.001).CONCLUSION:In this post-infectious rat model,the development of SIBO appears to be associated with a reduction in DMP-ICC.Further study of this rat model might help understand the pathophysiology of postinfectious irritable bowel syndrome. AIM: To investigate the interstitial cells of Cajal (ICC) number using a new rat model. METHODS: Sprague-Dawley rats were assigned to two groups. First group received gavage with Campylobacter jejuni (C. jejuni) 81-176. Second group was gavaged with placebo.Three months after clearance of Campylobacter from the stool, precise segments of duodenum, jejunum, and ileum were ligated in self-contained loops of bowel that were preserved in anaerobic bags. Dep muscular plexus ICC (DMP-ICC) were quantified by two blinded readers assessing the tissue in a random, coded order. The number of ICC per villus was compared among controls, Campylobacter was used in controls, Campylobacter used rats without small intestinal bacterial overgrowth (SIBO), and Campylobacter recovered rats with SIBO.RESULTS: Three months after recovery, 27% of rats gavaged with C. jejuni had SIBO.The rats with SIBO had a lower number of DMP-ICC than controls in the jejunum and ileum. Additionally there was shown to be a density threshold of 0.12 DMP-ICC / villus that wa s associated with SIBO.If ileal density of DMP-ICC was <0.12 ICC / villus, 54% of rats had SIBO compared to 9% among ileal sections with> 0.12 (P <0.05) -ICC / villus in more than one location of the bowel, 88% of these had SIBO compared to 6% in those who did not (P <0.001) .CONCLUSION: In this post-infectious rat model, the development of SIBO appears to be associated with a reduction in DMP-ICC. Future study of this rat model might help understand the pathophysiology of postinfectious irritable bowel syndrome.