EUS and ERCP: how the two procedures differ

What is EUS (endoscopic ultrasound)?

EUS combines an endoscope with an ultrasound probe at its tip. Because the probe sits close to the organs, it can give a detailed picture of the pancreas, bile ducts, gallbladder and the walls of the digestive tract.

It is commonly used to examine a suspected problem seen on a scan, to look for small stones in the bile duct, and, when needed, to take a tiny tissue sample for testing.

What is ERCP?

ERCP also uses an endoscope, along with X-ray imaging and fine instruments passed through the scope into the opening of the bile and pancreatic ducts.

It is mainly used for treatment: removing stones from the bile duct, placing a stent to keep a blocked duct open, or relieving a blockage that causes jaundice.

The main differences

• Purpose: EUS mainly examines and samples; ERCP mainly treats
• Imaging: EUS uses ultrasound from inside; ERCP uses X-ray to guide treatment
• Typical question answered: EUS asks what is there; ERCP fixes a duct problem
• Preparation: both need fasting and are usually done with sedation

Why the right test matters

Using the procedure that matches the problem avoids unnecessary risk. Doctors often start with blood tests and a scan, then decide whether EUS, ERCP, both or neither is appropriate. Sometimes EUS is done first to confirm a stone, so ERCP is used only if treatment is needed.

Before and after the procedure

• You will be asked to fast for several hours beforehand
• Tell the doctor about blood thinners, diabetes medicines and any allergies
• Most people are sedated and do not feel the procedure
• Someone should come with you, and you may be observed for some hours afterwards
• Your doctor will explain risks specific to your situation and what to watch for at home