Endoscopic mucosal resection is performed with a long, narrow tube equipped with a light and video camera. During EMR of the upper digestive tract, the doctor passes this tube (endoscope) down your throat into your esophagus, stomach or upper part of the small intestine (duodenum). To reach the colon, the doctor guides the tube up through the anus. The doctor then inserts instruments through the tube to perform the procedure.

EMR is usually done to treat a health condition. However, your doctor may also collect samples of tissue during the procedure. Examination of this tissue can help your doctor make a diagnosis. For example, if you have cancer, EMR can help determine if the cancer has spread to tissues beneath the digestive tract lining.