The side-viewing duodenoscope is considered the standard for ERCP procedure as it allows a better view of the major duodenal papilla, rendering cannulation easier. In patients with reconstructed gastrointestinal anatomy, as in patients with Billroth II gastrectomy or Roux-en-Y operation, the afferent loop entrance is hidden, and at a sharp angle, the afferent loop is elongated, and the papillary position is reversed.
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