What Happens During an ERCP
Knowing What to Expect Makes All the Difference
For many patients, the anxiety surrounding an ERCP procedure comes not from the procedure itself but from not knowing what is going to happen. When you understand exactly what occurs from the moment you arrive to the moment you leave the recovery area, the unknown becomes familiar and manageable. At Alnoor Diagnostic Centre in Shadman, Lahore, we believe an informed patient is a calm patient — and a calm patient has a better experience.
Step One — Arrival and Pre-Procedure Assessment
When you arrive at the centre on the day of your ERCP, the first thing that happens is a pre-procedure assessment by the nursing team. Your identity is confirmed, your fasting status is checked, and your medical history, current medications, and allergies are reviewed. Blood pressure, pulse, and oxygen saturation are recorded as baseline measurements.
An intravenous line — a small cannula — is inserted into a vein in your hand or forearm. This line is used to administer the sedation medication and any other drugs needed during or after the procedure. You will be asked to remove dentures, glasses, and jewellery, and you will change into a hospital gown.
Your gastroenterologist will visit you before the procedure begins to confirm the plan, answer any last-minute questions, and obtain your informed consent. This is your opportunity to raise anything you are uncertain about.
Step Two — Positioning and Sedation
You will be brought into the procedure room and positioned lying on your left side on the procedure table, with your knees gently bent. This position allows the endoscope to navigate the natural curves of the digestive tract most comfortably.
A plastic mouthguard is placed between your teeth to protect both your teeth and the endoscope as it passes through. A monitoring clip is attached to your finger to continuously measure your oxygen levels throughout the procedure. Sedation is then administered through your intravenous line. The medication takes effect within seconds, making you deeply relaxed and drowsy. Most patients have little or no conscious memory of the procedure that follows.
A throat spray may also be used to numb the back of the throat, reducing any gagging sensation as the endoscope is introduced.
Step Three — Inserting the Endoscope
Once the sedation has taken effect, the gastroenterologist gently introduces the endoscope through the mouthguard and into the back of the throat. The endoscope is a long, flexible tube approximately the width of a finger, with a high-definition camera and a light at its tip. Air is gently introduced through the endoscope to open the digestive tract and improve visibility.
The scope passes smoothly down the oesophagus and into the stomach. The gastroenterologist examines the lining of the stomach as the scope advances. From the stomach, the scope continues into the duodenum — the first portion of the small intestine. The entire passage from mouth to duodenum takes only a few minutes in experienced hands.
Step Four — Locating the Ampulla of Vater
Once inside the duodenum, the gastroenterologist identifies a small raised opening on the inner wall called the ampulla of Vater. This is the point where both the common bile duct and the pancreatic duct drain into the small intestine. It is the critical landmark around which the entire ERCP procedure is centred.
Locating the ampulla requires careful examination of the duodenal wall. In patients who have had previous stomach surgery or anatomical variations, this step may take additional time and skill. Once the ampulla is clearly identified, the working phase of the procedure begins.
Step Five — Cannulation and Contrast Injection
A fine, flexible catheter is passed through the working channel of the endoscope and carefully introduced into the opening of the ampulla. This step — called cannulation — requires precision and experience. The catheter must enter the bile duct rather than the pancreatic duct, which share the same small opening.
Once the catheter is correctly positioned inside the bile duct, contrast dye is injected gently through it. The dye fills the bile duct system and makes it visible on the fluoroscopy screen — the real-time X-ray monitor positioned alongside the procedure table. The gastroenterologist watches the dye as it travels through the bile duct, revealing the shape, width, and contents of the duct with clarity. Gallstones appear as filling defects — dark shadows within the contrast column. Strictures appear as narrowings. A dilated duct indicates downstream obstruction.
If the pancreatic duct also needs to be examined, the catheter is repositioned and contrast is injected into the pancreatic duct separately.
Step Six — Treatment During the Same Procedure
Once the diagnosis is confirmed on fluoroscopy, treatment is performed immediately without ending the procedure. This is what makes ERCP uniquely valuable compared to any purely diagnostic investigation.
If gallstones are present in the bile duct, a sphincterotomy is performed — a small, precise cut made at the ampulla using an electrosurgical wire to widen the bile duct opening. Small stones are then swept out using a balloon catheter passed through the endoscope. Larger stones are captured in a wire basket and extracted directly. Very large stones are first crushed using a mechanical lithotripter before removal.
If a stricture is causing obstruction, a guidewire is advanced through the narrowed segment and a stent — a small plastic or metal tube — is deployed across the stricture to hold it open and restore bile flow.
If a tissue diagnosis is needed from a suspicious area, a brush or small biopsy forceps is passed through the catheter to collect cells from the bile duct wall.
Each of these steps is performed under continuous fluoroscopic guidance, with the gastroenterologist watching the real-time X-ray screen throughout.
Step Seven — Completing the Procedure and Recovery
Once the intended diagnostic and therapeutic goals have been achieved, the endoscope is gently and smoothly withdrawn. The entire procedure typically lasts between 30 minutes and one hour, depending on the complexity of findings and the treatment performed.
You are then moved to the recovery area where the nursing team monitors your vital signs, oxygen levels, and level of consciousness as the sedation gradually clears. Most patients become alert within 30 to 60 minutes. Mild bloating and throat soreness are common and settle quickly. Once the team is satisfied that your observations are stable and you are comfortable, you are allowed to take small sips of water and then progress to light food.
You will be discharged into the care of the adult companion who accompanied you, with clear written instructions about what to expect at home, which symptoms to watch for, and when to resume normal medications and activities.
ERCP at Alnoor Diagnostic Centre, Lahore
At Alnoor Diagnostic Centre in Shadman, Lahore, our experienced gastroenterologists perform ERCP in a fully equipped endoscopy facility with a dedicated team committed to your comfort and safety at every step. From the moment you arrive to the moment you leave, you are in experienced hands.