Observation of the horizontal part of the duodenum by upper gastrointestinal endoscopy is not routinely performed due to the physical burden to patients. Determining in which patients observation of the horizontal part of the duodenum by upper gastrointestinal endoscopy should be attempted remains a challenge. We actively observe the horizontal part of the duodenum by upper gastrointestinal endoscopy in cases in which balloon-assisted endoscopy is considered. We report two patients in whom the horizontal part of the duodenum could be observed by upper gastrointestinal endoscopy combined with manual compression of the umbilical region.
