Gastrointestinal motility has evolved from an esoteric laboratory tool into a sophisti- cated diagnostic technique that is now widely used clinically to guide in management of complex gastrointestinal problems. Today, it is the most rapidly growing subspecialty within gastroenterology. Previously, many of the gastrointestinal motility problems were either ignored or attributed to a disturbance of "psyche." But with the growing knowledge and understanding of how a dysfunction of the gastrointestinal muscle and nerves can cause disease, we are at the threshold of a revolution in our approach to...