Gastroscopy vs. Colonoscopy: What’s the Difference?

The human digestive system is a complex network responsible for breaking down food, absorbing nutrients, and eliminating waste.

However, various conditions can affect different parts of this system, leading to discomfort, pain, and serious health concerns.

To diagnose and treat gastrointestinal (GI) disorders, doctors use endoscopic procedures like gastroscopy and colonoscopy.

 

Both gastroscopy and colonoscopy involve the use of an endoscope—a flexible tube with a tiny camera—to examine different parts of the digestive system.

However, these procedures target different areas, diagnose different conditions, and require different preparation methods.

 

If your doctor has recommended one of these procedures, understanding the differences, similarities, and what to expect can help ease any anxiety and ensure you’re well-prepared.

 

What Is Gastroscopy?

 

Definition and Purpose

Gastroscopy, also known as esophagogastroduodenoscopy (EGD), is a diagnostic procedure used to examine the upper digestive tract, which includes:

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

A gastroscope is inserted through the mouth and passed down the esophagus to visualize and assess any abnormalities in these areas.

 

Why Is Gastroscopy Performed?

 

Doctors may recommend a gastroscopy for several reasons, including:

• Persistent heartburn (GERD)
• Difficulty swallowing (dysphagia)
• Unexplained nausea or vomiting
• Upper abdominal pain or bloating
• Suspected ulcers
• Gastrointestinal bleeding
• Unexplained weight loss
• Screening for stomach cancer or celiac disease

How Gastroscopy Is Performed

 

• Preparation: Patients must fast for at least 6 to 8 hours before the procedure to ensure the stomach is empty.
• Sedation: A mild sedative or local anesthetic spray may be used to reduce discomfort.
• Insertion of the Gastroscope: The doctor inserts the gastroscope through the mouth and gently advances it through the esophagus, stomach, and duodenum.
• Evaluation & Biopsy: The doctor examines the tissue lining and may take a small sample (biopsy) for further testing.
• Completion: The procedure usually takes 10 to 20 minutes. Patients may experience mild throat discomfort afterward.

 

What Is Colonoscopy?

 

Definition and Purpose

Colonoscopy is a diagnostic procedure used to examine the lower digestive tract, specifically:

• Rectum
• Colon (large intestine)

A colonoscope is inserted through the anus and advanced through the colon to identify abnormalities such as polyps, inflammation, and cancerous growths.

 

Why Is Colonoscopy Performed?

 

Doctors recommend colonoscopy to detect and diagnose conditions such as:

• Colorectal cancer screening (especially for individuals over 45 years old)
• Removal of polyps before they become cancerous
• Chronic diarrhea or constipation
• Unexplained rectal bleeding
• Irritable Bowel Syndrome (IBS) or Inflammatory Bowel Disease (IBD)
• Abdominal pain, bloating, or changes in bowel habits
• Monitoring for previous history of colorectal cancer or polyps

 

How Colonoscopy Is Performed

 

1. Preparation: Patients must follow a colon cleansing regimen the day before the procedure, which involves drinking a special laxative solution to clear the bowels.
2. Sedation: Most patients receive mild sedation to ensure comfort.
3. Insertion of the Colonoscope: The doctor inserts the colonoscope through the anus and advances it through the colon.
4. Evaluation & Biopsy: The doctor examines the colon lining, removes any polyps, and may take a biopsy if needed.
5. Completion: The procedure takes 30 to 45 minutes. Patients may experience mild bloating due to the air introduced during the procedure.

 

Key Differences Between Gastroscopy and Colonoscopy

 

Both gastroscopy and colonoscopy are endoscopic procedures used to examine different parts of the digestive system. While they share similarities, they serve distinct purposes, target different areas, and require different preparation methods.

Understanding their key differences can help patients feel more informed and prepared for these procedures.

 

Area of Examination

The most significant difference between gastroscopy and colonoscopy is the area of the digestive tract they examine:

Gastroscopy (EGD) examines the upper digestive tract, which includes the:

• Esophagus (the tube that connects the mouth to the stomach)
• Stomach
• Duodenum (the first part of the small intestine)

Colonoscopy focuses on the lower digestive tract, specifically:

• Rectum
• Colon (large intestine)

 

Gastroscopy Is Used to Diagnose:

 

• Gastroesophageal reflux disease (GERD)
• Peptic ulcers
• Esophageal varices (enlarged veins in the esophagus)
• Hiatal hernia
• Gastritis (inflammation of the stomach lining)
• Celiac disease
• Esophageal or stomach tumors

Colonoscopy Is Used to Diagnose:

 

• Colorectal cancer (CRC) screening
• Polyps (small growths in the colon that may develop into cancer)
• Diverticulosis and diverticulitis
• Ulcerative colitis and Crohn’s disease (forms of inflammatory bowel disease)
• Chronic diarrhea or constipation
• Unexplained rectal bleeding

 

How the Procedure Is Performed

 

Gastroscopy:

• A thin, flexible tube (gastroscope) with a camera is inserted through the mouth.
• It is guided down the throat, through the esophagus, into the stomach, and into the duodenum.
• The doctor examines the lining of the upper digestive tract and may take a biopsy if necessary.

Colonoscopy:

• A colonoscope, a longer and slightly wider tube, is inserted through the anus.
• It is gently advanced through the rectum and colon to examine the lining of the large intestine.
• The doctor may remove polyps, take biopsies, or address sources of bleeding.

 

Preparation Before the Procedure

 

Gastroscopy Preparation:

• Patients must fast for 6 to 8 hours before the procedure to ensure the stomach is empty.
• Clear liquids may be allowed up to 2 hours before the procedure.
• No bowel preparation is needed.

Colonoscopy Preparation:

• Patients must follow a strict bowel-cleansing regimen the day before the procedure.
• This includes drinking a laxative solution to clear the colon of stool.
• A clear liquid diet is recommended for 24 hours before the procedure.
• Proper preparation is crucial for an accurate examination.

 

Sedation and Comfort Level

Both procedures can be uncomfortable, but sedation helps ease any discomfort.

 

Gastroscopy:

• Usually performed with mild sedation or a throat-numbing spray to reduce gag reflex.
• Some patients may experience mild throat irritation after the procedure.

Colonoscopy:

• Typically requires moderate to deep sedation for patient comfort.
• Patients may experience mild bloating or cramping due to air introduced during the procedure.

 

Duration of the Procedure

 

• Gastroscopy is a shorter procedure, typically lasting 10 to 20 minutes.
• Colonoscopy takes 30 to 45 minutes, depending on findings such as polyps that need removal.

 

Recovery Time and Aftercare

 

Gastroscopy:

• Patients can typically resume eating and drinking within a few hours.
• If sedation was used, driving should be avoided for 24 hours.
• A mild sore throat may persist for a few hours.

Colonoscopy:

• Patients may experience gas, bloating, or mild cramping due to the air introduced during the procedure.
• Normal eating can resume, but a light diet is often recommended at first.
• If polyps were removed, minor rectal bleeding may occur.
• Driving should be avoided for 24 hours if sedation was used.

 

What to Expect After the Procedures

 

Recovery After Gastroscopy

• Patients may have a mild sore throat or bloating.
• Normal eating and drinking can usually resume within a few hours.
• If sedation was used, patients should avoid driving for 24 hours.

Recovery After Colonoscopy

• Patients may experience gas, bloating, or mild cramping.
• A light diet is recommended for the first few hours.
• If polyps were removed, minor rectal bleeding may occur.
• Driving should be avoided for 24 hours if sedation was used.

 

When Should You See a Doctor?

 

If you experience any of the following symptoms, a gastroscopy or colonoscopy may be necessary:

• Chronic acid reflux or heartburn
• Difficulty swallowing or persistent nausea
• Blood in stool or black, tarry stools
• Unexplained weight loss
• Chronic diarrhea or constipation
• Severe abdominal pain or bloating

 

Conclusion

 

Both gastroscopy and colonoscopy are essential diagnostic tools for evaluating gastrointestinal conditions. While gastroscopy focuses on the upper digestive tract, colonoscopy examines the lower digestive tract.

If your doctor recommends either procedure, understanding the differences, preparation, and recovery process can help ease concerns. Both procedures play a crucial role in early detection and prevention of serious GI conditions.

If you have ongoing digestive symptoms, don’t wait—schedule a consultation with a gastroenterologist today.

 

Get in Contact with Dr. Deetlefs

 

If you would like to book an appointment with a gastrointestinal (GI) specialist or would simply like more information on a particular GI topic, don’t hesitate to use our online booking form or call Dr. Deetlefs at 021 551 867.