A device used to look at tissues in the esophagus, stomach, and intestines. It is a capsule with a lens, a light, a camera, a radio transmitter, and a battery inside. The patient swallows the capsule and it takes video pictures of the inner walls of the esophagus, stomach, and intestines as it travels through the digestive tract. The pictures are sent to a small wireless receiver that is worn on the waist of the patient and are later viewed on a computer. The wireless capsule endoscope is passed from the body in the stool. Also called capsule endoscope.