Bloating is a clue—not a diagnosis
Small intestinal bacterial overgrowth (SIBO) describes an abnormal increase or change in bacteria in the small intestine. Common complaints include bloating, gas, abdominal discomfort, diarrhea, constipation, nausea, or early fullness. These symptoms also occur with IBS, celiac disease, food intolerance, constipation, medication effects, and other conditions.
I do not diagnose SIBO from symptoms alone.
My evaluation starts here
- When symptoms occur in relation to meals and bowel movements
- Prior abdominal surgery, infections, diabetes, or motility problems
- Current medications and repeated antibiotic exposure
- Constipation, diarrhea, reflux, and unintentional weight change
- Previous testing, treatment response, and recurrence pattern
- Signs that point toward a different diagnosis
Breath testing
Hydrogen and methane breath testing may be useful when the history supports SIBO or intestinal methanogen overgrowth. The patient drinks a specified carbohydrate solution and provides timed breath samples. Preparation matters because diet, laxatives, antibiotics, smoking, and exercise can affect results.
Breath testing has limitations, so I interpret the pattern together with symptoms and history rather than treating one number as the entire diagnosis.
Treatment must fit the person
Treatment may involve prescription medication, nutrition changes, or both, depending on the diagnosis and clinical context. Very restrictive diets are not a permanent solution and can reduce dietary variety. My goal is to control symptoms while protecting nutritional adequacy.
When SIBO keeps returning, it is important to ask why. Constipation, altered motility, anatomy, medication effects, and underlying disease may need attention. Repeated treatment without examining contributors can lead to a cycle of temporary relief and recurrence.
When to seek prompt care
Blood in stool, black stool, persistent vomiting, fever, dehydration, severe pain, anemia, or unexplained weight loss warrants medical assessment rather than self-treatment for SIBO.