Endoscopic mucosal resection (EMR) is a procedure to remove cancerous or other abnormal lesions from the digestive tract. EMR is performed with a long, narrow tube equipped with a light, video camera, and other instruments. During EMR of the upper digestive tract, the endoscope is passed down your throat to reach an abnormality in your esophagus, stomach or upper part of the small intestine (duodenum). When EMR is used to remove lesions from the colon, the tube is guided up through the anus. Although EMR is primarily a treatment procedure, it's also used to collect tissues for use in diagnosis. If cancer is present, EMR can help determine if the cancer has invaded tissues beneath the digestive tract lining.