Ulcerative colitis and Crohn's disease are the inflammatory bowel diseases with a continuously increasing of prevalence. Their exact causes are still not well known and, more than that, they are raising up serious issues of diagnosis. The same difficulties of diagnosis are encountered in the case of the colonic angiodysplasia or ischemic colitis (IC). Colonic angiodysplasia is a common vascular abnormality of the gastrointestinal tract, being diagnosed mostly in the elderly persons, in a similar manner to the IC. For all these diseases comorbidities plays their important role both as causes of the onset and aggravating factors during the evolution. The differential diagnosis between these three conditions needs a complex and multidisciplinary approach, involving at least clinical evaluation, endoscopic and imaging assessments, and histopathological exam.