Interest has been increasing on the mechanism of intestinal angina and the surgical correction of superior mesenteric artery disease. The pain of intestinal angina is described as severe generalized cramping abdominal pain which may radiate to the back. The onset is typically a short time after food intake and the duration one to three hours or longer. Patients try to avoid pain by eating smaller and smaller meals. Most authors1-6 have attributed the pain to relative intestinal ischemia during digestion. However, there is little evidence available to show that normal digestion is in fact accompanied by an increase in blood flow to the gut. The present study undertook to examine the effect of digestion and exercise on the blood flow in the superior mesenteric artery in the conscious dog. Materials and Methods Fourteen mongrel dogs of either sex weighing 13 to 19 kg (29 to 42 lb) (mean, 16.4