The stomach is an organ full of sympathy for other sufferers. Hardly any of the viscera connected with the intestine, or the bowel itself, can be affected without the stomach playing its part in the disturbance also. This it does by pouring out an excess of secretion, and by tumultuous and irregular activities. It speaks so loudly that its voice only is heard. Sir B. G. A. Moynihan, 19211 PYLORIC OBSTRUCTION and gastric retention are often confused, but they are by no means synonymous. Although mechanical obstruction, obviously, produces gastric retention, the latter may occur without any mechanical obstruction whatsoever. When it is mistakenly assumed that gastric retention necessarily means gastric obstruction, muddy thinking and misguided therapy result. The purpose of this paper is to describe the types of gastric retention, the clinical situations in which they may occur, and by a classification of these conditions to make