Billroth II reconstruction is one option to restore gastrointestinal continuity following partial gastrectomy (figure 1) . Partial gastrectomy with reconstruction can be performed to treat complications of peptic ulcer disease (such as perforation, bleeding, penetration, and duodenal stricture) or gastric carcinoma localized at the antrum. This reconstruction technique was named after Theodor Billroth, who first performed it in January 1885. Although significantly less often performed in recent years for complications of peptic ulcer disease because of changes in management (H2 blockers and proton pump inhibitors), the Billroth II operation remains a commonly used reconstruction after distal stomach resection. (See "Partial gastrectomy and gastrointestinal reconstruction", section on 'Gastrointestinal reconstruction' and "Total gastrectomy and gastrointestinal reconstruction", section on 'Gastrointestinal reconstruction'.)
Because of the surgically altered anatomy, diagnostic and therapeutic endoscopic retrograde cholangiopancreatography (ERCP) is more difficult in patients with previous Billroth II gastrectomy compared with patients with native anatomy. The papillary area in the second part of the duodenum can only be reached through the afferent loop. As a result, the papilla of Vater appears upside-down compared with its orientation during standard ERCP (figure 1).
The endoscopist performing ERCP in a Billroth II patient has to consider and overcome the following issues:
●Choosing the appropriate endoscope
●Entering the afferent loop