Megaesophagus and Megaduodenum Found Incidentally on a Routine Chest Radiograph During a Health Examination.

Chronic idiopathic intestinal pseudo-obstruction (CIIP) caused by impaired intestinal peristalsis leads to intestinal obstructive symptoms. A 20-year-old man had marked esophageal dilatation that was found incidentally on chest radiography during a health examination. Chest/abdominal contrast-enhanced computed tomography and endoscopy showed marked esophageal and duodenal dilatation without mechanical obstruction. Upper gastrointestinal series and high-resolution esophageal manometry revealed absent peristalsis in the dilated part. CIIP was suspected in the patient's father, suggesting familial CIIP. The patient likely had signs of pre-onset CIIP. This is the first case of suspected CIIP in which detailed gastrointestinal tract examinations were performed before symptoms appeared.