Rules on fasting before surgery are based on assumptions that anesthesia reactions might cause patients to throw up during a procedure and hamper breathing, but research has shown clear liquids within two hours actually decreases that risk, according to John Abenstein, president of the American Society of Anesthesiologists and a Mayo Clinic anesthesiologist. OR teams are sometimes reluctant to adopt the less-restrictive policies out of concern patients won’t follow directions and come in for surgery having had a glass of milk or cola, and then surgery has to be delayed, Dr. Abenstein says. But when patients consume clear liquids correctly, they feel much better after surgery, he says.