SIBO

The intestinal tract can be divided broadly into four compartments: esophagus, stomach, small intestine and large intestine – also known as the colon. Throughout the intestinal tract there live bacteria – some of which help us digest food and nutrients, stimulate or immune system and help with bowel movements. There are relatively few bacteria esophagus, stomach and small intestines. In the stomach, acid destroys bacteria. In the small intestine, bile, digestive enzymes also prevent bacteria growth. Food and liquid move through the small intestines fairly quickly and there is little time for bacteria to fester and grow. The large intestine on the other hand houses far more bacteria – over a trillion bacteria. This is largely because the colon is very accommodating – its physically larger and things move much slower in the colon. As such bacteria have time to fester and grow. This is rarely a problem in the colon – occasionally too much stool (i.e. constipation) can result in gas or bloating.

In patients with SIBO – there is an excessive amount of bacterial growth in the small intestines. This may happen for a number of reasons including a sudden slow down in small intestinal movement due to infections, medications or recent surgery. In some instances, the intestinal movement (also known as peristalsis) is inherently slow. As a result, bacteria have time to sit and fester. In other instances, immune disorders allow bacteria that are normally easily killed and kept in check – to suddenly grow out of control.

Patients with SIBO will often complain of abdominal pain, gas and bloating. The overgrowth of bacteria may also cause poor absorption of nutrients. As a results, patient often have watery diarrhea or greasy/fatty stools due to malabsorption of fat.

Blood tests in patients with suspected SIBO will show nutrient and vitamin deficiencies including low protein levels. Patient often have anemia, Vitamin B3, B6, B12 deficiencies. These blood test can be suggestive of SIBO. However, a better test for SIBO is a specialized breath test that can measure how much bacteria there is in the small intestine. can be diagnosed with a specialized breath test. The gold standard for diagnosis is upper endoscopy with a sample of small intestine fluid to exactly measure the amount of bacteria.

The treatment of SIBO typically in volve antibiotic treatment to kill off the excessive bacteria. Reseeding the gut with healthy bacteria in the form of probiotics also has some benefit. A low-FODMAP diet has also showed some promise in treating SIBO. Low-FODMAP foods are low fermentable foods and can help with gas and bloating. The link below provides a comprehensive review on diagnosis and treatment of SIBO in children.