In a survey of the literature on the subject of intestinal obstruction, one is struck by the looseness and inaccuracy of the terms used to describe the various conditions encountered.The words obstruction, occlusion, atresia, stenosis and aplasia are often interchanged, which confuses the reader as well as distorts the meaning of the writer. For this reason an explanation of the terms as used here is indicated.By obstruction is meant any blocking or clogging of the lumen of the intestine which hinders the passage of intestinal contents. An occlusion is a complete closure of the lumen of the intestine; it is commonly referred to as a complete obstruction. Atresia, as its Greek derivation \ g=b\ -\ g=t \ \ g=r \ \ g=h\ \ g=t \ \ g=o\ \ g=f s\ without a boring) implies, is an imperforation, an absence or a closure of the intestinal lumen. The word has been used by many, in this strict sense, but to most it signifies not only the occlusion of the bowel from some intrinsic congenital error of development but any degree of constriction or narrowing of the lumen due to some developmental defect of one or all of the intestinal coats-it includes both occlusion and stenosis. Atresia presupposes the existence, at some time in the development of the bowel, of a lumen, of which there is subsequently complete (occlusion) or partial (stenosis) obliteration. In such a comprehensive sense is it used here. Aplasia, on the other hand, is the absence of the development of a lumen, i. e., a condition in which presumably a lumen never did exist and in which frequently even the mesentery is absent.Duodenal obstruction in the newborn is congenital or acquired. The acquired type is either (a) mechanical and caused by such fetal accidents as hernia, volvulus, Meckel's diverticulum, bands and From the surgical service of De Downloaded From: http://archpedi.jamanetwork.com/ by a University of Manitoba User on 06/06/2015 infection, or (b) adynamic and neuromtiscular in character and much the same in origin as Hirschsprung's disease is thought to be. The etiology of the congenital forms is still far from clear and remains theoretic. Meckel, Bal four, Tandler, Kreuter, Cautley and Albers felt that it is due to the failure of the bowel to acquire a lumen during embryonic life.