pyloric obstruction and dilation /pīlôr″ik/ [Gk, pyle, gate, ouros, guard; L, obstruere, to build against, dilatare, to widen] , a reaction of the stomach to pyloric obstruction, which increases the resistance to the expulsion of partly digested food from the stomach. As a result, the stomach may become hypertrophied, then dilated. Excessive consumption of food and beverages contributes to the condition.