Hello, this is Sungmo Best Internal Medicine, performing colonoscopies in Wolgot-dong, Siheung. A colonoscopy is an examination that helps check colon health and detect various diseases in advance so they can be addressed. However, many people find the preparation process more difficult than the examination itself.
Can I drink coffee before the exam? How should I fast? How should I take the medication? These are the most frequent questions we receive by phone before a visit. So, in this article, we've compiled all the information you've been curious about in one place. The better you follow the precautions, the cleaner your bowels will be, and the more accurate the examination will be, so we recommend reading to the end if you have an upcoming exam.
How to Take Bowel Cleansing Medication
To obtain clear examination results, your bowels must first be thoroughly emptied. For this, you will take bowel cleansing medication the day before and on the day of the examination.
- When to take: Generally, twice—the evening before the exam and the morning of the exam.
- After taking: You will start frequenting the restroom about 1-2 hours later, repeating the process of emptying your bowels until almost no stool comes out.
- Water intake: If you don't drink enough water with the medication, your bowels may not be thoroughly emptied.
The day before the examination, please eat light foods, and on the day of the examination, you must fast. For those who find liquid medication burdensome, please note that there are also capsule-form cleansing agents available recently. If you are curious about the examination procedure, you can check it in advance under Examination Guide.
How Much Does a Colonoscopy Cost?
The cost you bear may vary depending on the individual, as health insurance or private insurance coverage conditions differ for each person. The ranges below are for simple reference only.
| Category | Approximate Cost |
|---|---|
| When health insurance is applicable | Around 50,000-100,000 won |
| When health insurance is not applicable | Around 150,000-300,000 won |
| When choosing a sedative endoscopy | Additional 100,000-200,000 won |
If you are eligible for the National Health Screening Program, you may be able to receive it at a lower cost, so please actively utilize that opportunity.
Can I Really Not Drink Coffee Before the Exam?
This is the most frequently asked question before visiting our internal medicine clinic in Wolgot-dong. Some people think that coffee might be okay during fasting because it has almost no calories, but to put it simply, you should avoid it.
- The caffeine in coffee can stimulate the stomach and intestines, interfering with bowel cleansing.
- The dark color of coffee can obstruct the view inside the intestines, hindering examination interpretation.
- Coffee with sugar or milk can leave residues in the large intestine.
Instead, it's okay to drink clear water just enough to moisten your lips.
Foods to Adjust 2-3 Days Before the Exam
| Foods to Avoid | Recommended Foods |
|---|---|
| Fruits with seeds, like kiwi and grapes | White rice porridge, white rice |
| Seaweed, such as kelp, seaweed, and gim | Steamed egg, tofu |
| Nuts, such as peanuts and almonds | Clear broth |
| Oily foods like fried foods, pork belly, and chicken, and dairy products like milk and cheese |
These foods have a sticky, hard-to-digest texture, making them prone to leaving residues in the intestines.
How to Prepare on the Day of the Exam
- Visit in light clothing.
- If having a sedative endoscopy, use public transportation rather than your own car, and if possible, be accompanied by a guardian.
- Do not schedule urgent appointments after the examination; allow sufficient time for recovery.
If you are planning a visit from Wolgot-dong or Jangok-dong, Siheung, it is convenient to check our Clinic Hours first.
Even if the preparation process feels cumbersome, the more diligently you follow it, the more accurate the examination will be. Please feel free to ask any questions via chat.
Dr. Kim Seonhoo (Specialist in Gastroenterology, Specialist in Gastrointestinal Endoscopy) · Meet Our Medical Team · Last reviewed 2026-08-06