The double pylorus.
D000368:Aged; D005260:Female; D005753:Gastric Mucosa / Q000002:abnormalities; D005773:Gastroscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011708:Pylorus / Q000002:abnormalities*; D013272:Stomach Diseases / Q000209:etiology*; D013276:Stomach Ulcer / Q000150:complications*