Endoscopy is a procedure that allows direct visualization of parts of the gastrointestinal tract and, if necessary, therapeutic manoeuvres to be undertaken. An endoscope is the requisite instrument; rigid endoscopes are not now generally used except for sigmoidoscopy.
Investigation of the oesophagus, stomach and proximal duodenum can be achieved with a gastroscope under light sedation.
A endoscopic retrograde cholangiopancreatography (ERCP) allows visualization of the pancreas and the biliary tree.
A colonoscope allows investigation of the large bowel and terminal ileum. However, the whole of the large bowel can only be examined in 85-90% of subjects.
A sigmoidoscope allows visualization of the rectum. A flexible sigmoidoscope
permits visualization of the sigmoid colon and descending colon.