Glossary

SIBO

Small Intestinal Bacterial Overgrowth. A condition in which abnormal bacterial overgrowth in the small intestine contributes to symptoms or malabsorption.

Breath Test

A noninvasive test that measures gases in exhaled breath after ingestion of a sugar substrate.

Hydrogen

A gas produced by microbial fermentation. A rise in breath hydrogen can support SIBO in the right clinical context.

Methane

A gas associated with constipation-predominant symptoms in some patients. Methane is produced by archaea, not bacteria.

Hydrogen Sulfide

A gas that may be relevant in some patients with diarrhea-predominant symptoms, depending on test availability and interpretation.

Motility

The coordinated movement of the gastrointestinal tract.

Migrating Motor Complex

A fasting motility pattern that helps clear the small intestine between meals.

Malabsorption

Impaired absorption of nutrients.

Low-FODMAP Diet

A dietary approach that temporarily reduces fermentable carbohydrates to help identify symptom triggers.

Rifaximin

A minimally absorbed antibiotic commonly discussed in SIBO treatment. Use should be directed by a clinician.