SIBO test in Seoul, prepared properly

What the SIBO test in Seoul measures

Small intestinal bacterial overgrowth, or SIBO, means there are more bacteria than normal in the small intestine, where relatively few should live. These bacteria ferment carbohydrates early in digestion and produce gas, which can cause bloating, belching, wind, diarrhea, abdominal discomfort and, over time, poor absorption of nutrients such as vitamin B12.

The SIBO test in Seoul at VEI Clinic is a non-invasive way to look for this. After an overnight fast you give a baseline sample, drink a measured sugar solution, usually glucose or lactulose, and then give samples into collection bags every 15 to 20 minutes for about two to three hours. Hydrogen and methane are gases made by gut microbes, not by your own cells, so an early rise suggests bacteria are fermenting the sugar higher up in the gut than they should.

Dr. HyunSung Park, a board-certified internal medicine specialist with gastroenterology subspecialty training, decides whether the test is appropriate and which sugar to use before you book a test date.

Who the test may help, and who needs a different test

The test is not the right first step if you have red-flag symptoms such as weight loss, bleeding, anemia or night-time diarrhea; those need investigations such as blood tests, stool tests and often endoscopy or colonoscopy, which we arrange by referral to a hospital. Celiac disease, lactose intolerance, H. pylori and thyroid problems can mimic SIBO and may be checked first.

• Persistent bloating, distension or excess gas, especially when it starts soon after meals.
• Chronic loose stools, or constipation with bloating, which can be linked to methane-producing organisms.
• Risk factors such as previous bowel surgery, diabetes affecting gut movement, long-term acid-suppressing medicine, or certain motility disorders.
• IBS-type symptoms where SIBO is being considered as one contributor.

How to prepare: the details matter

These tests are easily disturbed, so please follow the preparation closely. We give you written English instructions when you book.

• No antibiotics for about four weeks beforehand, if medically safe, and tell us about recent bowel preparation for colonoscopy.
• Stop laxatives and gut-motility medicines for about a week, unless your doctor says otherwise. Ask us about probiotics and acid-reducing medicines.
• The day before, eat a simple low-fermentation diet such as plain rice, eggs, plain chicken or fish, and water, avoiding fiber, beans, dairy, fruit and sweeteners.
• Fast for about 12 hours beforehand, drinking water only. Do not smoke, chew gum or exercise on the test morning, and brush your teeth without swallowing toothpaste.
• If you have diabetes, check with Dr. Park first, because fasting and the glucose drink can affect your blood sugar.

Results, false positives and honest limits

Under widely used North American consensus criteria, a rise in hydrogen of at least 20 parts per million above baseline within 90 minutes suggests SIBO, and methane of 10 parts per million or more at any point suggests intestinal methanogen overgrowth, now often called IMO, which is linked to constipation.

The test has real limitations. With lactulose, fast gut transit can bring the sugar to the colon early and give a false positive. With glucose, sugar is absorbed early, so overgrowth further down may be missed. Poor preparation, recent antibiotics and some bacteria that make hydrogen sulfide, which standard tests do not measure, can also cause misleading results. A positive test is a clue, not a final diagnosis, and Dr. Park interprets it together with your symptoms and other tests.

What happens next, and red flags

If the result and symptoms fit, treatment is usually a course of antibiotics chosen for the gas pattern, such as rifaximin, along with addressing the underlying cause, for example reviewing medicines or managing diabetes. A short-term diet such as low-FODMAP with structured reintroduction may help symptoms. Because SIBO often returns if the underlying cause persists, we plan follow-up rather than repeated courses without review. Rifaximin availability and insurance coverage vary, and we discuss options before prescribing.

Seek urgent care and call 119 if you have severe or worsening abdominal pain, vomiting blood, black or bloody stools, high fever, or signs of dehydration such as dizziness and very little urine.