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