Endoscopy

An endoscopy is a test to look inside your body. A long, thin tube with a small camera inside, called an endoscope, is passed into your body through a natural opening such as your mouth. Your GP may refer you for an endoscopy if you're having certain symptoms. It will usually be done at an endoscopy unit in a hospital.

It is a procedure were a flexible tube with fibre optic camera is inserted through the mouth to visualise the upper gastrointestinal tract 

Colonoscopy

A colonoscopy (koe-lun-OS-kuh-pee) is an exam used to look for changes — such as swollen, irritated tissues, polyps or cancer — in the large intestine (colon) and rectum. During a colonoscopy, a long, flexible tube (colonoscope) is inserted into the rectum.

It is a procedure were a flexible tube with fibre optic camera is inserted through the anus to visualise the large intestine and terminal part of small intestine.

Endoscopic Retrograde Cholangiopancreatography 

ERCP is a procedure that helps in diagnosis and treatment of bile duct and pancreatic diseases like bile duct stones, narrowing of bile duct causing jaundice, chronic pancreatitis, growth near the opening of bile duct. It is done with the help of a specialised Gastroscope and Xray machine 

ERCP is mainly used in the treatment of obstructive jaundice secondary to bile duct stones or narrowing of the bile duct in biliary tract cancer and also in management of long term pain in patients with chronic pancreatitis