SIBO: The Root Cause of IBS?

Dr. Preet Khangura, ND

Small intestinal bacterial overgrowth, or SIBO, might not be a term that you have read or heard about. This is unfortunate because extensive research has shown that 70 – 80% of people who have been diagnosed with Irritable Bowel Syndrome (IBS), test positive for SIBO. Before explaining why this is a crucial finding, let’s take a quick look at what much of the medical field calls IBS.

Irritable bowel syndrome is what I like to call a “lazy diagnosis”. The reason I describe it in such a manner is because when patients complain of digestive issues such as excess burping/flatulence, abdominal bloating, abdominal cramping, diarrhea, constipation, and there is no inflammation or lesions to be found in the gastrointestinal tract, many doctors give up on finding the root cause of the symptoms and label the patient as having a “syndrome” – an irritable bowel syndrome to be exact. Treatment options are usually minimal and directed only towards reducing symptoms on a daily basis.

An important note is that IBS is much different than IBD, or inflammatory bowel disease. IBD is present when inflammation and/or lesions have been proven to be the cause of the digestive problems. Autoimmunity usually plays a large role in the occurrence of the lesions. Two common examples of IBD are ulcerative colitis and Crohn’s disease.

Now let’s take a look at SIBO. Our intestines are separated into two groups – small intestines and the large intestine (or colon). Food is digested down into its simple, absorbable components in the small intestines, while the waste moves into the large intestine for eventual evacuation during bowel movements. 80% of our intestinal bacteria is meant to reside in our large intestine, while only about 20% is meant to live in our small intestines. However, sometimes much more than 20% of our bacteria can end up residing in the small intestines. Primary reason is due to a dysfunctional migrating motor complex (MMC). When this occurs, it can lead to an overgrowth of bacteria in the small intestines, which ends up being the cause of the excess gas, bloating, cramping, diarrhea and/or constipation. How do extra bacteria in the wrong place cause all of this, you may ask? Well, the bacteria’s primary food sources are polysaccharides and fiber. Therefore, the bacteria go after starchy carbohydrates, most grains, and a wide range of fruits and vegetables when you eat them. As mentioned earlier, the small intestines are where our food it digested down for nutrient absorption. However, once the bacteria intervene in this process, it causes fermentation of the improperly digested food to occur. This is what then causes all of the indigestion symptoms. Therefore, no lesions or autoimmunity is needed for the daily indigestion symptoms that negatively affect so many people’s lives.

I diagnose (via hydrogen/methane breath testing) and treat a lot of SIBO in my practice. It brings me a lot of happiness when patients who have been labeled as an “IBS case” for 10 or 20 years, excitedly tell me that they now no longer have any indigestion symptoms. All it took was seeing a doctor who doesn’t quite agree with a syndrome being a cause of what can be crippling symptoms. So if you have been dealing chronic digestive problems with no known cause, testing for SIBO might just be what the naturopathic doctor ordered.