The upper endoscope.
Under sedation, same day as your colonoscopy.

Inflammation, ulcers, polyps, hiatal hernia and early structural changes in the oesophagus, stomach and duodenum; biopsies can be taken during the same procedure.

A gastroscopy does not examine the small or large intestine beyond the duodenum. A colonoscopy covers the lower tract, and the two are complementary, not substitutes for each other.

A colonoscopy examines the lower digestive tract; a gastroscopy examines the upper tract. Partner centers commonly perform both under one sedation session, covering the full length of the gut in a single visit.

Is a gastroscopy painful?

Under sedation you normally do not wake up during the procedure, and most patients report minimal discomfort afterward. A throat that feels uncomfortable for 2–3 days is the most common after-effect.

Can I have a gastroscopy and colonoscopy on the same day?

Yes. This is the standard pairing at partner centers, done under one sedation session to avoid two separate recovery periods.

How do I prepare?

At least 10 hours of fasting, and on the day nothing at all, water included. The preparation guide sets out the partner centres' full instructions, and your coordinator sends the exact timing once your appointment is confirmed.

Does finding stomach cancer earlier actually change the outcome?

The population figures say stage at diagnosis matters more than anything else about the disease. Among cancers diagnosed in Korea between 2019 and 2023, gastric cancer found at localized stage had a 5-year relative survival of 97.6%; found at distant stage it was 7.5%. Two things have to be said alongside that. It describes populations and not any individual, and a screening programme flatters its own survival figures by construction, because finding a disease earlier lengthens measured survival even when it does not change the date of death. What the figures support is that the stage a cancer is found at is not incidental, and that a country screening at Korea's volume finds 65.3% of gastric cancers still localized against 32% in the United States.

Why is a gastroscopy part of a routine checkup here but not at home?

Because the underlying disease burden differs and the screening programmes were built around it. Korea has offered biennial gastric screening since 1999, to adults aged 40 to 74, so the equipment, the sedation practice and the reading volume all exist as ordinary infrastructure. In 2025 the national recommendation went further and made gastroscopy effectively the only primary method, on domestic evidence that it beats the upper-GI series on both accuracy and mortality reduction. No equivalent population screening programme for gastric cancer exists in the United States, which is why the test tends to appear there only after symptoms.