Medical Definition of Percutaneous endoscopic gastrostomy (PEG) Our Percutaneous Endoscopic Gastrostomy (PEG) Main Article provides a comprehensive look at the who, what, when and how of Percutaneous Endoscopic Gastrostomy (PEG) Percutaneous endoscopic gastrostomy (PEG): A surgical procedure for placing a feeding tube without having to perform an open laparotomy (operation on the abdomen). The aim of PEG is to feed those who cannot swallow. PEG may be done by a surgeon, gastroenterologist (GI specialist). It is done in a. hospital or outpatient surgical facility.