To the Editor.— The answers to the question about "gas pains" from Dr Morrison 1 neglected to mention one of the major contributors to postoperative distention. The use of a straw for the administration of fluids from cups is a major source of intestinal air. Complaints about gas pain decrease if straws are avoided and obviously the mechanism is decreased aerophagia. The content of CO 2 in a bottle of a Coca-Cola is 490 mL. Added to the volume of fluid, this produces an effective displacement of about 700 mL. 2 The problem of carbonated beverages is a real one and they probably should be avoided.