Inflammatory bowel diseases: controversies in the use of diagnostic procedures

The term inflammatory bowel disease (IBD) denotes a genetically, immunologically and histopathologically heterogeneous group of inflammatory bowel disorders classified at present time as ulcerative colitis (UC), Crohn's disease (CD) and indeterminate colitis (IC). Diagnosis of IBD is based on a non-strictly defined combination of clinical and diagnostic parameters. In order to guide the treatment, patients must be assessed by determining IBD phenotype, disease extension and distribution, extraintestinal manifestations, disease behavior, disease severity and drug responsiveness. Each element of the diagnostic process cannot be looked at alone, but has to be incorporated into general clinical assessment, bearing in mind that different phenotypes and age groups require specific diagnostic solutions. Advances in technology provided the possibility for the assessment of the entire digestive system with endoscopy leading the way. Sophisticated imaging methods made the analysis of the bowel wall with its vascularity and adjacent mesentery possible. The challenge is still the small bowel, where a combination of endoscopy and imaging methods is used. The use of imaging methods should be, among other things, guided by level of irradiation which is especially important in young patients and in patients requiring repeated investigations. Using abdominal ultrasound as a low-cost, noninvasive procedure, one has to take into account that it is very operator-dependent method. In UC, endoscopy is used for the evaluation of the extent and activity of the disease and to assess complications like stricture, dysplasia and cancer. UC is classified by the disease extent into proctitis, left-sided colitis and extensive colitis beyond the splenic flexure. Pediatric patients with UC have more extensive disease than adults with rectal sparing in up to 30% of patients. The severity of mucosal changes are reported as Baron endoscopic score. Endoscopic findings correlate well with clinical activity and are commonly incorporated into Mayo index, combination of clinical Truelove Witts index and Baron score. Complications like strictures require imaging methods as supplement to endoscopy. The incidence of CD, particularly in children and adolescents, has risen during the past decade, with children often having extensive and severe disease The nature of CD requires the use of wide array of endoscopic and imaging methods, placed properly in the diagnostic algorithms for specific disease phenotypes and complications and adapted for specific age groups. Endoscopic features of CD are very variable and can be quantified as Crohn's Disease Endoscopic Index of Severity (CDEIS) or Simple Endoscopic Score for CD (SES-CD). Disease activity is most commonly assessed by CDAI. Perianal disease activity should be measured by PDAI due to low CDAI scores in these patients. The activity of CD in children should be assessed by the Pediatric Activity Index. IC is part of the IBD spectrum where chronic colitis cannot be defined as either UC or CD after sequential colonoscopies and colonic biopsies or at colectomy.