Endoscopic Ultrasound (EUS)
An endoscope with an ultrasound probe at the tip — gives detailed images of the pancreas, bile ducts, and surrounding lymph nodes. Can take precise biopsies through the gut wall.
Results
Verbal findings same day. Cytology/biopsy results 5-10 days.
Video explainer
2:47
This article is educational and does not replace your doctor's advice. Seek urgent care for any red-flag symptoms.
What is it?
EUS combines endoscopy with ultrasound. The probe is placed inside the stomach or duodenum, providing extremely detailed images of nearby organs (pancreas, bile ducts, lymph nodes, deep structures of the esophagus and stomach wall). Fine needle aspiration (FNA) or biopsy (FNB) can sample tissue safely without surgery.
Why is it done?
Pancreatic mass evaluation and biopsy (cancer or cyst), staging GI cancers (esophageal, gastric, rectal, pancreatic), evaluating bile duct stones missed by other tests, assessing pancreatic cysts, draining pancreatic fluid collections, drainage of pseudocysts.
Who needs it?
- Pancreatic mass or cyst on imaging
- Staging of esophageal, gastric, pancreatic, or rectal cancer
- Evaluation for choledocholithiasis when MRCP unclear
- Sub-mucosal lesions in the GI tract
- Drainage of pancreatic pseudocysts
Before the procedure
- Fasting 6-8 hours.
- Stop blood thinners as directed.
- Discuss any sedation concerns.
- Arrange a driver.
During the procedure
Sedation through IV. You lie on your left side. The endoscope is passed through the mouth into the stomach or duodenum. The doctor uses the ultrasound to image surrounding organs. If a biopsy is needed, a thin needle goes through the channel of the scope and into the target lesion under ultrasound guidance. Takes 30-60 minutes.
After the procedure
Recovery 30-60 minutes. Sore throat for a few hours. Mild abdominal discomfort if biopsy taken. Resume normal diet same day; avoid strenuous activity for 24 hours. Pathology takes 5-10 days.
Risks
- Bleeding from biopsy site: <1%
- Pancreatitis if pancreatic biopsy: 1-2%
- Perforation: rare
- Sedation reactions: rare
- Infection if cyst drainage: rare with antibiotics
When you get results
Alternatives if you decline
CT, MRI, and PET can image these areas but with less detail and inability to biopsy. Surgical biopsy is more invasive.
Questions to ask your doctor
Save this list or print it before your appointment — doctors appreciate prepared patients.
- Is biopsy planned during my EUS?
- What's the chance of finding cancer?
- Will I need additional tests after?
Medically reviewed by: SGA Patient Education Panel · Last reviewed 24/04/2026