Gastroscopy vs. Colonoscopy: What's the Difference?

Gastroscopy and colonoscopy are two of the most common endoscopic procedures, but they examine different ends of the digestive tract. Understanding the distinction is key to knowing what to expect if Dr. Loots recommends one for you.

Gastroscopy: A Look at the Upper GI Tract

A gastroscopy (also known as an upper endoscopy or OGD) is a procedure used to visually examine your upper digestive system. This includes your oesophagus, stomach, and the first part of your small intestine (the duodenum).

• Why it's done: To investigate symptoms like persistent heartburn, difficulty swallowing, upper abdominal pain, nausea, or bleeding.
• The Instrument: A thin, flexible tube with a light and camera at its tip, called a gastroscope, is gently passed through your mouth and down your throat.
• Preparation: Preparation is simple. You'll just need to fast for several hours before the procedure to ensure your stomach is empty.

Colonoscopy: A View of the Lower GI Tract

A colonoscopy, on the other hand, is used to examine the entire large intestine (colon) and rectum. It is the gold standard for colorectal cancer screening.

• Why it's done: For cancer screening, to investigate changes in bowel habits, rectal bleeding, or abdominal pain, and to look for the cause of chronic constipation or diarrhoea.
• The Instrument: A longer, flexible tube called a colonoscope is passed through the rectum into the colon.
• Preparation: This is the more intensive part. It requires a special diet for a day or two, followed by a liquid bowel preparation solution to completely clean out the colon.

Key Takeaway

In short, a gastroscopy looks at the "upper" part of your gut, while a colonoscopy looks at the "lower" part. Both are incredibly valuable diagnostic tools performed comfortably under sedation in our Cape Town in-rooms suite.