What Is SIBO? All About Small Intestinal Bacterial Overgrowth

SIBO, also known as small intestinal bacterial overgrowth, causes digestive symptoms that are very common like belly, pain, bloating, and bowel changes.

sibo diet

A SIBO diet will help relieve such symptoms as bloating, gas, cramping, and diarrhea.

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SIBO is the acronym for a disease called small intestinal bacterial overgrowth. [1-3] It is hard to know how common SIBO is. It causes digestive symptoms that are very common like belly, pain, bloating, and bowel changes. Many cases of SIBO may be missed because the diagnosis requires special testing. [3] It is important to know about SIBO, so you can let your doctor know if you have the signs and symptoms. Untreated SIBO can lead to serious problems from malnutrition. [1-3]

What Causes SIBO?

SIBO is caused by an abnormal growth of bacteria in your small intestine. Your small intestine is the first 20 feet of your digestive system after your stomach. Foods that you eat normally move quickly through this part of your digestive tract as they are digested and absorbed. [1]

Unlike the last part of your digestive tract – your colon – there is not much bacteria in your small intestine. However, if you have a condition that slows down movement through your small intestine, bacteria can have a chance to multiply. Slow-moving food and drink can be a breeding ground for bacteria. [1-3]

Some people are at higher risk for slowed digestion in the small intestine. You could be at higher risk for SIBO if you have had:

  • Surgery on your stomach or small intestine, such as a bypass procedure or ulcer surgery
  • Radiation therapy to your belly for cancer
  • A disease like irritable bowel syndrome, inflammatory bowel disease, scleroderma, celiac disease, or diabetes
  • Or if you take a medication that slows down digestion like a muscle relaxant, narcotic, or acid blocker [1-3]

Symptoms of SIBO

Symptoms of SIBO can seem like a stomach flu at first but they don’t go away. They can include:

  • Belly pain or bloating
  • Loss of appetite and feeling full soon after starting to eat
  • Nausea or vomiting
  • Diarrhea or constipation
  • Weight loss
  • Fatigue [1-3]

Over time SIBO can cause malnutrition because you are not absorbing enough nutrients from your small intestine. These includes fats, carbohydrates, and proteins. It can also include important vitamins like A, D, E, K, and vitamin B12. You may also develop lactose intolerance. Complications of malnutrition can include nerve damage, osteoporosis, anemia, and kidney stones. [1-3]

How Is SIBO Diagnosed?

If your doctor suspects SIBO, the best way to diagnose the condition is to put a tube down into your small intestine to take a sample of your intestinal fluid and check for bacteria. Another test is a breath test. Bacteria produce a gas called methane that can be measured by a breath test. Your doctor may also do an imaging study to look for a blocked intestine and do a blood test to look for vitamin deficiencies. [1-3]


Treatment of SIBO depends on the cause, but for most people, treatment will include taking an antibiotic. In some cases, people who have a blocked intestine due to surgery or scar tissue may need surgery to restore flow through the intestine. [1-3]

People who have recurrent SIBO, long-term SIBO due to a disease, or who have developed malnutrition, may be treated with diet therapy. [1-3] These diets are hard to do on your own, and should be managed by a diet care provider. Examples include the FODMAP diet and a predigested elemental diet. Some people may benefit from probiotics. Diet treatments are controversial and not all studies agree that they are helpful. [3]

When to Call Your Doctor

In most cases, once SIBO is diagnosed, the right treatment will help. Let your doctor know if you have symptoms of SIBO that are not going away, especially if you had any abdominal surgery, or have any of the other risk factors. Let your doctor know if you have loss of appetite or unwanted weight loss. Get medical attention right away if you have severe abdominal pain. [1]



  1. Mayo Clinic, Small intestinal bacterial overgrowth (SIBO)
  2. Johns Hopkins Medicine, Small Intestinal Bacterial Overgrowth (SIBO)
  3. Clinical and Translational Gastroenterology, Small Intestinal Bacterial Overgrowth: Clinical Features and Therapeutic Management

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Chris Iliades, MD

Chris Iliades has an MD degree and 15 years of experience as a freelance writer. Based in Boothbay Harbor, Maine, his byline has appeared regularly on many health and medicine … Read More

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  • I have sibo & everyone’s bacteria are diff….I can have alcohol biscuits cakes pies but very small portions & I get no reaction on the other had red meat destroys me gotta listen to your body.

  • Great summary, but constipation needs to be added as a symptom, especially for those patients with methane based SIBO.

  • Um.. they said to LIMIT those things. Gotta read. Just diagnosed with sibo and there is so much conflicting info on what you can have. So basically rice, meats, broths, hard cheeses, and green crunchy vegetables. I am just not messing around with the legumes or fruits or other dairy. Also need to list weight GAIN as a symptom too. It happens when the body goes into starvation mode.

  • This is quite confusing. The list of foods you can eat here does not align with the Monash Univerosty app that you refer to. For examples, sweet potatoes are a no go. Perhaps you can update your info?

  • I was diagnosed with Sibo. I’ve looked at foods to eat & not eat. Not a big selection for me!! Can I get menus to go by somewhere thx

  • When my husband was diagnosed with methane-based SIBO, I had to re-learn how to cook. I started following Dr. Siebecker’s list to develop my own recipes; when my lists got too long, I put them on a website, thinking maybe what I’d done might help others. Every recipe uses only ingredients from the safe “green” column of Dr. Siebecker’s ingredient list, which we found was helpful for my hubby’s healing. Maybe the recipes might help you too… http://www.mysiborecipes.com

  • Rhen thanks for reading this article and for your comments. There is widely conflicting advice on what to eat on the SIBO diet as the research is conflicting. I recommend if you have SIBO you ask your doctor for their recommended list.

  • Margarine? That thing a molecule away to plastic? Lol. No thanks. I’ll stick to olice oil, sunflower oil and even a bit of butter instead.

  • I been burping/belching for one year and still going on. I was diagnosed with SIBO, just finished the antibiotics. My problem is trying to find the right food to eat without having acid reflux. I can’t have a peaceful workout without burping. Some doctors stated it can be swallowing air while I eat or drink. Can someone help me with this? This is so miserable.

  • I have the same issue with belching. I was just diagnosed but with the elevated hydrogen. I’ve been on the FODMAP Diet but I haven’t noticed any difference even though I’ve been doing it for a good month or so. I just want some relief and I’m waiting to hear back from the doctor. Concerned about taking antibiotics because I reacted so many different ones. I have been taking probiotics for sometime now. Perhaps I’ll give me different ones that will make me feel better. The bloating feeling is really very uncomfortable, not to mention some of the other, uncomfortable symptoms.

  • Am currently researching the effects of toxins in particular heavy metals and parasitic infestation on the microbiome. Wondering if they contribute to SIBO symptoms. Perhaps a thorough body cleanse of the above together with nutraceuticals including probiotics and appropiate diet to restore the mocrobiome and gut lining. Once the gut is healthy consuming whole nourishing foods like fruit should not be an issue.

  • Grapefruit seed extract oil of oregano woodworm will kill the parasites along with Garden of Life Primal Defense has all the right strains of probiotic to keep the sibo down along with diet lowering stress and exercise and I actually take valium for the pain in my intestines it helps immensely I advise seeing a psychiatrist and a psychologist because it is meta physical

  • Diagnosed with SIBO. Doctor prescribed x if’s an however cost is prohibitive, 1840 dollars for two week regimen

  • I just received what would cost $8600+ (100 pills) in the US of the antibiotic for SIBO from Canada for $90 including shipping.

  • So why would you take an antibiotic when that is what destroys the microbiome?
    Also, does prednisone set you up for this? Had 10 day prednisone taper, and problems (diarrhea,
    bloating) ever since off .

  • Prednisone has its own withdrawal complications. Water retention, nausea, constipation are all related to Prednisone withdrawals. I was on a super high dose of steroid for an eczema outbreak and while on it did alright actually. But the withdrawals once coming off have been similar to SIBO. My sister in law has SIBO and the similarities in gut health are scary.

  • “Hydrogen “sounds like you are Lactose intolerant. Try cutting out milk, soft cheese, butter, thin cream. You can get “Arla Lactose free” milk etc in UK. Only eat “Live ” Yoghurt (Not Pasteurised) and cut out sugar.

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