SUMMARY
Background: Inflammatory disease of Crohn affects the entire digestive tract, with extra-intestinal manifestations and immune disorders.Objectives: This work aims to represent the histopathological aspects of Crohn‘s disease and the establishment of pathogenic bacteria as causal agents.Methodology: The histopathological aspects of the disease were studied on a colonic resection specimen and on intestinal biopsies with colorations topographic staining. Pathogenic bacteria responsible for Crohn‘s disease have also been isolated and identified. The study is continued to establish a correlation between the disease and exposure to infections by unusual bacteria, particularly pathogens (Salmonella, Shigella, Streptococcus pyogenes, Klebsiella).Results : The macroscopic appearance of the disease presented transmural involvement and can be complicated by abscesses and fistulas, microscopic appearance indicated the infiltrate of inflammatory cells (lymphocytes, plasma and cells) and lymphoid follicles after topographic staining.Crohn’s disease is an idiopathic disease, it is assumed that it is a deregulation of the immune system due to an infectious agent in genetically predisposed people.In our work, we studied the microbiota of intestine and stool of Crohn’s patients in which we found certain bacteria including Proteus mirabilis with a predominance of E. coli. Other pathogenic bacteria were found like Salmonella spp., Shigella spp., Klebsiella spp. and Streptococcus pyogenes. Two cases which tested positive on Ziehl Neelsen stain represented Mycobacterium avium paratuberculosis.Conclusion: The histopathological aspect of CD can be better visualized and identified on surgical specimens than on endoscopic biopsies, which helps to monitor the evolution of the disease and must be accompanied by clinical, serological and radiological exploration.