title: The evolution of the double pylorus.
mesh_terms: D005747:Gastric Fistula / Q000209:etiology*; D005773:Gastroscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D010439:Peptic Ulcer Perforation / Q000150:complications*; D011708:Pylorus / Q000473:pathology*; D013276:Stomach Ulcer / Q000150:complications*