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Bloating, Gas, Irritable Bowel Syndrome—Do You Have SIBO?

Small intestine bacterial overgrowth, or bacterial overgrowth syndrome-- also referred to as SIBO (pronounced see-bow)-- is the culprit behind a large number of digestive disorders. In fact, SIBO is linked to approximately 70 percent of Irritable Bowel Syndrome cases!

Around 70 million Americans are living with a digestive disorder such as irritable bowel syndrome (IBS), and 74 percent of Americans experience digestive discomforts such as gas, bloating, diarrhea, or abdominal pain. SIBO is likely involved in a lot of these cases.

The small intestine is the part of the digestive tract that connects the stomach to the colon. It is about 20 feet long, and unlike the large intestine, it contains few bacteria. The small intestine is a vital part since it is where the body absorbs most of the nutrients from the foods we eat. Therefore, an unhealthy small intestine creates conditions for an unhealthy body.

People with SIBO often observe symptoms from eating like bloating, abdominal pain, diarrhea, constipation, or a combination of diarrhea and constipation, in addition to gastroesophageal reflux disease and nausea. They may also have food reactions and sensitivities, particularly to carbs. And because SIBO affects absorption in the small intestine, there are often other symptoms like brain fog, depression, anxiety, fatigue, and weight loss.

There are three kinds of gases that bacteria produce with SIBO. These consist of:

  • Hydrogen
  • Methane
  • Hydrogen Sulfide

Hydrogen-related SIBO is defined by abdominal gas and bloating and frequent bouts of loose stool or diarrhea.

Methane-related SIBO is characterized by abdominal gas and bloating, as well as constipation.

Hydrogen sulfide is defined by abdominal gas and bloating, along with foul, rotten egg smelling flatulence, bad breath and/or a bad taste in the mouth, and perhaps more severe diarrhea.

SIBO is not actually an infection but the excessive colonizing of particular bacteria in the small intestine. Around 66% of SIBO cases are chronic. The common symptom of intestinal gas with SIBO occurs from the bacterial fermentation of carbs. This is why SIBO diets decrease or get rid of particular types of carbs.

The Root of SIBO

One of the leading causes of SIBO is a previous bout of food poisoning. A lot of the research done on the causes of SIBO has been done by Mark Pimental, MD, who has a lab research program at Cedars-Sinai. He has found that for some people, food poisoning and other infectious gastroenteritis and diverticulitis are related to the development of Irritable Bowel Syndrome (IBS). This also causes low-grade inflammation, increased intestinal permeability, and autoimmunity in the gut. Therefore, there is poor motility in the small intestine that results in bacteria moving from the colon into the small intestine. There appears to be a direct association between IBS and SIBO

More root causes of SIBO include the long-term use of Proton Pump Inhibitors (PPIs) such as omeprazole, lansoprazole, rabeprazole, pantoprazole, and esomeprazole. Other causes include individuals with diseases that impact intestinal muscle motility, like gastric bypass surgery, Parkinson's disease, diabetes, celiac disease, and other disorders.

Testing SIBO

There are two methods to test for SIBO One involves getting fluid from the small intestine and culturing it. This method is done by gastroenterologists and is invasive and expensive. Also, only a small part of the small intestine (jejunum) is tested. The other testing method which is more practical involves gathering breath samples and looking for a rise in the gases related to SIBO (which I mentioned earlier). The lab we use with patients is Trio-Smart ®, which is the only breath test that measures all three gases.

Super Treatments for SIBO

Several different approaches can be used to treat SIBO. When the kind of SIBO is determined with signs, symptoms, and testing, a protocol has to be followed closely for several months.

One of the challenges with bacteria involved in SIBO is making collections of microbes that secrete slimy substances called a biofilm. These biofilms protect the bacteria and make it more difficult for the immune system and treating agents to get to the SIBO bacteria. For some cases, we have to use agents that break down biofilms. Examples include colloidal silver, calcium EDTA, N-acetylcysteine, glutathione, and alpha-lipoic acid.

Foods that Feed SIBO

The most well-studied gut-friendly diet is the low-FODMAP diet (low fermentable oligosaccharide, disaccharide, monosaccharide, and polyols). Short-chain carbs are poorly absorbed in the small intestine. The purpose of the low-FODMAP diet is to cut back on, or remove, these readily fermentable foods, reducing both SIBO and IBS symptoms. SIBO sufferers need to avoid the following high FODMAPs: 

  • Fructose (fruits, honey, high-fructose corn syrup [HFCS], etc)
  • Lactose (dairy)
  • Fructans (wheat, garlic, onion, inulin, etc)
  • Galactans (legumes such as beans, lentils, soybeans, etc)
  • Polyols (sweeteners containing isomalt, mannitol, sorbitol, xylitol, etc)
  • Stone fruits (avocadoes, apricots, cherries, nectarines, peaches, plums, etc)

When the patient is doing better by adhering to one or more of the protocols below, they do not have to maintain the low-FODMAP diet, which can be difficult to sustain long-term for many people. 

Herbs to the Rescue 

Several herbal extracts can be helpful for treating SIBO. Examples of ones we have found effective include thyme, oregano, lemon balm, sage, berberine, Oregon grape, bilberry, and many Chinese herbs. We use solutions that have published clinical effectiveness. 

Antibiotic Options 

There are also cases of SIBO where we need to use antibiotics. Examples include Rifaximin and Neomycin. However, if we use these antibiotics, we follow herbal therapy since antibiotic treatment has a high relapse rate. 

Pro-Motility Agents Needed 

Because there is such a high occurrence of reduced intestinal motility, individuals with SIBO prone to constipation need long-term support to keep their small intestinal motility healthy. Natural agents include ginger, artichoke extract, and bitter herbals, such as Swedish Bitters. The daily use of fiber supplements like psyllium and chia seeds are a good idea. 


There is quite a variation in individuals with SIBO and their response to probiotics. In recent times we have been using a product called SIBO Wellness. It includes probiotics that support healthy gut flora, protect the integrity of the small intestine, and help treat SIBO and the toxins related to SIBO.