Understanding EGD Scope Depth: How Far Does an Upper Endoscopy Really Go?

If your doctor has recommended an EGD (esophagogastroduodenoscopy), you’re not alone. It’s one of the most common procedures to evaluate symptoms like heartburn, upper abdominal pain, or trouble swallowing. But for many patients, a pressing question arises: how deep does the endoscope go during an EGD? Knowing what to expect not only eases anxiety but helps you better understand how this diagnostic tool works.

This article explores the depth and reach of an EGD scope, what organs it examines, how the procedure is performed, and how it compares with other gastrointestinal (GI) tests.

An EGD, also known as upper endoscopy, is a minimally invasive diagnostic procedure used to examine the upper gastrointestinal tract. This includes:

• Esophagus (the tube that carries food from your mouth to your stomach)
• Stomach
• Duodenum (the first part of the small intestine)

Doctors perform an EGD to evaluate symptoms such as:

• Chronic heartburn or GERD
• Nausea or vomiting
• Difficulty swallowing (dysphagia)
• Unexplained weight loss
• Suspected ulcers or tumors
• Anemia from suspected gastrointestinal bleeding

The EGD endoscope typically travels from the mouth to the second part of the duodenum, covering a distance of about 60–70 centimeters (roughly 24–28 inches), depending on the patient’s anatomy.

Here’s a breakdown of the EGD scope journey:

1. Mouth and Throat (Oropharynx):

   The scope is inserted through the mouth while the patient is sedated. A bite block is used to protect teeth and the scope.

2. Esophagus:

   The scope moves through the esophagus to check for inflammation, strictures, varices, or tumors.

3. Stomach:

   The camera examines the gastric fundus, body, antrum, and pylorus for ulcers, erosions, tumors, or signs of gastritis.

4. Duodenum (First and Second Portions):

   This is the deepest point the EGD reaches. The scope passes through the pyloric sphincter into the duodenal bulb and descending duodenum, visualizing any ulcers, masses, or bile duct abnormalities.

In most standard EGDs, the second portion of the duodenum (D2) is the endpoint. Occasionally, if clinically necessary, the scope may be advanced slightly further, but this is rare.

While the EGD covers the upper GI tract effectively, it does not reach the jejunum, ileum, or colon. If deeper parts of the small intestine need evaluation, doctors may order:

• Enteroscopy (uses longer scopes)
• Capsule endoscopy (a swallowed camera pill)
• Colonoscopy (for large intestine)

By visualizing the upper GI tract, an EGD can detect:

• Gastroesophageal reflux disease (GERD) and related esophagitis
• Barrett’s esophagus (a precancerous condition)
• Hiatal hernia
• Peptic ulcers
• Gastric or duodenal polyps
• Celiac disease (via duodenal biopsy)
• Helicobacter pylori infection
• Upper GI bleeding sources
• Tumors or malignancies

Not exactly. The actual depth can vary based on:

• Patient’s height and anatomy
• Presence of obstructions, strictures, or surgical alterations
• Sedation tolerance and gag reflex
• Clinical goal of the procedure

That said, in a routine EGD, the goal is always to reach the second part of the duodenum, and most scopes are designed to easily achieve that depth.

1. Preparation:
   • Fasting for 6–8 hours prior
   • Medication review
   • Sometimes local anesthetic and IV sedation
2. Procedure:
   • You lie on your left side
   • A mouthpiece is placed
   • The flexible scope is inserted and advanced
   • Air may be blown to distend the stomach
   • Biopsies may be taken (painless)
3. Duration:
   • The procedure lasts 10–20 minutes
   • You’ll be monitored during recovery for 30–60 minutes

Most patients feel no pain during an EGD due to conscious sedation or anesthesia. Some may feel mild pressure or bloating from air insufflation, but you won’t feel the scope going deep into the stomach or duodenum.

When comparing an EGD to other gastrointestinal (GI) procedures in terms of scope depth and diagnostic reach, there are notable differences. An EGD, or upper endoscopy, involves inserting a flexible scope through the mouth to examine the esophagus, stomach, and the first two parts of the duodenum. This typically allows the endoscope to travel up to 70 centimeters into the digestive tract.

In contrast, a colonoscopy is performed via the rectum and is designed to evaluate the entire large intestine, reaching as far as the cecum, which can involve inserting the scope up to 150 centimeters or more.

For deeper evaluation of the small intestine, procedures like enteroscopy are used. These employ longer or double-balloon scopes that can reach well beyond the duodenum into the jejunum or ileum, depending on the method used.

Lastly, capsule endoscopy—a non-invasive test that involves swallowing a small camera—can capture images throughout the entire small intestine, making it useful when the origin of GI bleeding or obscure symptoms lies beyond the reach of standard endoscopes.

A: No. But endoscopic ultrasound (EUS) or ERCP (Endoscopic Retrograde Cholangiopancreatography) can help visualize and treat pancreatic or biliary conditions.

A: Not typically, as long as it’s performed by an experienced gastroenterologist. The scope is designed to flexibly navigate the upper GI tract without damaging tissues.

A: Yes. Besides diagnosis, EGD can treat bleeding ulcers, remove polyps, dilate strictures, and retrieve foreign objects.

Understanding how deep the endoscope goes during an EGD can help demystify the process for patients. The scope typically travels from the mouth to the second part of the duodenum—giving doctors a clear look at the upper GI tract. It’s a safe, effective, and minimally invasive way to diagnose and sometimes treat digestive disorders.

If you’re scheduled for an EGD, talk to your gastroenterologist about what they plan to evaluate and what findings might require further testing.