Various devices, systems, and methods that can be used in the treatment of obesity and related illnesses are disclosed. In some instances, a portion of the bowel of an obese patient is distended for a therapeutically effective period. The distention may be achieved by introduction of an object that is of foreign origin relative to the body of the patient into the bowel of the patient. In some instances, the distention is achieved by a medical device that transitions from an undeployed state, in which the medical device is introduced into the bowel of the patient, to an expanded state in which the medical device distends the bowel by an amount sufficient to trigger an intestinal-gastric brake in the patient.