Until just recently, the cause of IBS was not known and was more of a umbrella term given to whole range of digestive symptoms ranging from mild bloating and pain to chronic diarrhoea, constipation (or a mix of both) all of which can have a drastic impact on daily life…..
Sure, stress can play a big part in IBS, as does unidentified food intolerance’s however what has now been discovered is that Small Intestinal Bacterial Overgrowth or (SIBO) is responsible for up to 80% of IBS cases 
What on earth is SIBO?
Bacteria levels within the upper portion of the digestive tract (stomach and small intestine) should remain at relatively low levels, and for that reason there are several mechanisms in place that keep bacteria levels at bay. This starts with;
- good levels of stomach acid,
- adequate bile flow from the liver and gallbladder
- regular muscular contractions of the small intestine which act like ‘cleansing waves’ pushing the entire contents of the small intestine forward through the digestive tract (known as the migrating motor complex, MMC)
- A well-functioning ileocecal valve which prevents the contents of the large intestine (bacteria, faecal waste) flowing back up into the small intestine.
When one or more of these mechanisms are disrupted either through lifestyle factors, medications, past surgeries or gastrointestinal infections, bacteria levels in the small intestine begin to climb. This is where the problems begin!
Common Causes of SIBO
Are you ticking any of these boxes?
Medications for reflux and heartburn can lead to the development of SIBO. These commonly used medications include Somac, Nexium and Losec work to suppress stomach acid production however stomach acid itself is protective against harmful bacteria and other unwanted microbes. Chronic suppression of stomach acid levels mean bacteria levels in the small intestine can flourish 
Abdominal surgeries such as removal of appendix, c-section and conditions such as endometriosis may result in scar tissue and adhesions. Adhesions in the abdominal area may affect how well the ileocecal valve works 
Removal of the gallbladder impacts on bile flow and good bile flow is crucial for keeping bacteria levels in the small intestine under control. Studies show that removal of the gallbladder can increase the risk for developing SIBO, particularly after the 2-year mark post-surgery 
A past bout of gastro can also be a risk factor for SIBO even if symptoms occur months after the initial infection. Toxins that are released from the pathogenic ‘bug’ can damage the migrating motor complex (MMC) essentially paralysing the normal action of ‘cleansing waves’ allowing stagnation to occur and bacteria levels to rise 
Dietary and lifestyle factors such as a poor diet high in sweets, sugars and refined carbohydrates combined with factors such a history of antibiotic use, high alcohol intake and/or high stress levels can all contribute to the development of SIBO.
SIBO At Work, How The Damage Is Done
As foods passes through the small intestine, these misplaced bacteria begin to feed off or ‘ferment’ specific types of carbohydrates and in the process, produce an excess of unwanted gas. It is the excess gas produced during this fermentation process that causes many of the symptoms of IBS (and SIBO) including bloating, pain, chronic diarrhoea and/or constipation.
Interestingly, depending on the types of bacteria, levels of gas produced may be predominately hydrogen or methane. Each gas has its own set of symptoms with hydrogen dominant patients tending towards diarrhoea, while methane dominant patients tending to struggle more with constipation.
SIBO An Underlying Cause of Chronic Inflammation
Over time these misplaced bacteria and excess gas can lead to chronic inflammation of the gut and can affect the absorption of many nutrients. It is not uncommon for someone with SIBO to develop several nutritional deficiencies including iron, B12 and Vitamin D.
A chronically inflamed gut can also trigger a whole range of seemingly unrelated health conditions. This is due to the increased permeability of the gut lining (known as ‘leaky gut’) which allows partially undigested food particles into the blood stream. The immune system identifies these food particles as foreign and wastes no time in mounting an attack against these foreign invaders. As you can imagine over time this ongoing immune activation leads to chronic inflammation and gives rise to many different conditions which have been closely linked to SIBO including;
- Restless legs
- Interstitial cystitis
- Auto-immune disorders
- Inflammatory bowel disease (IBD)
Signs and symptoms of SIBO
Signs and symptoms of SIBO can range from mild to severe and will typically occur within 20 – 30 minutes after eating with bloating and pain normally felt in the upper abdomen region. The extra gas produced can also cause many other symptoms including;
- A tendency to bloat after almost ‘all foods’ in some cases even after water,
- Excessive belching and burping after meals,
- Feeling full very quickly,
- Bad breath,
- An intolerance to fatty and oily foods,
Not everyone with SIBO will have all these signs and symptoms however if you feel like you are ticking many of the boxes here you may want to investigate it further. Testing for SIBO is done through a breath test which measures the levels of gas produced after a challenge solution is drunk over a three-hour period.
The good news is, if SIBO is confirmed then it can be treated using a step by step approach that combines specific dietary guidelines with herbal and nutritional supplements that re-balance bacteria levels in the small intestine while also healing the gut and reducing systemic inflammation.
Addressing SIBO may not only mean an end to many years of uncomfortable and annoying digestive issues but also improvement in other areas including mental health, energy levels, skin health and conditions affecting the immune system including auto-immune disorders.
Wanting to look into SIBO further? Melanie is a registered practitioner with sibotest.com, founded by Dr Jacobi, one of Australia’s leading experts in the natural treatment of SIBO.
1. Ghoshal, U. C., & Srivastava, D. (2014). Irritable bowel syndrome and small intestinal bacterial overgrowth: Meaningful association or unnecessary hype. World Journal of Gastroenterology : WJG, 20(10), 2482–2491. http://doi.org/10.3748/wjg.v20.i10.2482
2. Dukowicz, A. C., Lacy, B. E., & Levine, G. M. (2007). Small Intestinal Bacterial Overgrowth: A Comprehensive Review. Gastroenterology & Hepatology, 3(2), 112–122. Viewed 21/02/2018
3. World J Gastroenteroly. 2012 Dec 14; 18(46): 6801–6808.
Published online 2012 Dec 14. doi: 10.3748/wjg.v18.i46.6801 Ileocecal valve dysfunction in small intestinal bacterial overgrowth: A pilot study, viewed 20/02/2018 at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3520169/
4. Rana SV, Kar J, Gupta R, et al. Effect of Post-Cholecystectomy on Small Intestinal Bacterial Overgrowth and Orocecal Transit Time in Gallstone Patients.Int J Dig Dis. 2016, 2:1. doi:10.4172/2472-1891.100023 viewed 20/02/2018 at
5. Dukowicz, A. C., Lacy, B. E., & Levine, G. M. (2007). Small Intestinal Bacterial Overgrowth: A Comprehensive Review. Gastroenterology & Hepatology, 3(2), 112–122.
6. What Is Sibo, SIBOtest.com, (2018) [Source}