Inclusion and exclusion criteria for this study. A total of 1,764 patients underwent color Doppler US examinations from January 2008 to March 2012; of these, 790 patients had CD. In total, 743 patients who did not undergo US before the operation and/or whose Limberg score of Doppler US was 0 or 2 were excluded. Forty-seven patients underwent surgery and had Grade 1, 3, or 4 Limberg score. Seven patients without small bowel lesions (colon lesions only) were excluded, and 30 patients with abscesses, fistulae, ileus, and/or difficulty in identifying the position between US findings and surgical specimens were also excluded.