Skip to main content

Bacterial Overgrowth Syndrome

Medically reviewed by Last updated on Mar 5, 2023.

Bacterial overgrowth syndrome (BOS) is a condition that causes too many bacteria to grow in your small intestine. You may have too many of one kind of bacteria, or several kinds of bacteria. It is important to manage health conditions that can lead to BOS, such as diabetic neuropathy or hypothyroidism. Your healthcare providers can help you manage symptoms such as diarrhea and abdominal pain.

Digestive Tract


Call your doctor if:

  • You have irregular or fast breathing or a fast or pounding heartbeat.
  • You have a headache, dizziness, or confusion.
  • You are urinating less than usual or not at all.
  • You have a fever.
  • Your signs and symptoms do not go away, or they come back, even after treatment.
  • You suddenly lose weight without trying.
  • You are more tired than usual or weak.
  • You have questions or concerns about your condition or care.


You may need any of the following:

  • Antibiotics are used to decrease the bacteria in your intestine. You may need to try more than one kind of antibiotic to find what works best.
  • Medicines may be used to help waste move through your intestines or empty your stomach more quickly.
  • Take your medicine as directed. Contact your healthcare provider if you think your medicine is not helping or if you have side effects. Tell your provider if you are allergic to any medicine. Keep a list of the medicines, vitamins, and herbs you take. Include the amounts, and when and why you take them. Bring the list or the pill bottles to follow-up visits. Carry your medicine list with you in case of an emergency.

What you can do to manage or prevent BOS:

  • Drink more liquids to prevent dehydration. Dehydration can develop if you have diarrhea several times each day. Drink liquids as directed. You may also drink an oral rehydration solution (ORS). An ORS has the right amounts of water, salts, and sugar needed to replace body fluids. Ask your healthcare provider where to buy ORS and how much to drink.
  • Talk to your healthcare provider about diarrhea medicine. Your provider will tell you if it is safe to take medicine to control diarrhea. This depends on what is causing your BOS. You may need prescription medicine, or you may be able to take over-the-counter medicine. Follow directions so you do not make abdominal pain worse or develop constipation.
  • Ask about probiotics. Probiotics are also called good bacteria. They can help protect you from harmful bacteria. Ask your healthcare provider if probiotics are right for you. You may be able to eat yogurt or other foods high in probiotics. Your provider may instead recommend a pill or liquid form.
  • Limit alcohol. Alcohol can lead to BOS. Alcohol can also make abdominal pain worse. A drink of alcohol is 12 ounces of beer, 5 ounces of wine, or 1½ ounces of liquor.
  • Work with healthcare providers to create meal plans. Nutrition changes may be used to stop bacterial overgrowth, or to manage your symptoms. Bacteria eat sugar, so your healthcare provider may recommend a low-carb or lactose-free diet. Lactose is milk sugar, found in dairy products and certain other foods. Your provider or a dietitian can help you create meal plans with the right calories and nutrition. Your provider may also recommend vitamin or mineral supplements if your levels are low.

Follow up with your doctor as directed:

Write down your questions so you remember to ask them during your visits.

© Copyright Merative 2023 Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes.

The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.