To prepare for a SIBO breath test and ensure accurate results, you usually need to follow a special low-residue diet the day before, avoid high-fiber and fermentable foods (like beans, whole grains, dairy, fruits, and vegetables), and eat only simple options such as plain white rice, eggs, chicken, or clear broth as instructed by your provider. Most labs require fasting for 8–12 hours before the test, and you should avoid smoking, chewing gum, or vigorous exercise the morning of the test. Certain antibiotics (typically stopped 2–4 weeks prior), probiotics (about 1 week prior), laxatives, and sometimes acid-reducing medications may need to be paused, but always confirm with your doctor before stopping anything. Carefully following your clinic’s exact instructions is important because even small deviations can affect the accuracy of your results.