IBS & SIBO Connections
Why Your IBS Diagnosis May Not Be Enough
If you’ve received an Irritable Bowel Syndrome (IBS) diagnosis or you’ve been managing IBS symptoms like bloating, abdominal pain, diarrhea, and constipation, you’re not alone…. Recent studies show that IBS affects approximately 10-15% of the entire U.S. population, and an astounding two-thirds of Americans report experiencing these types of recurrent digestive symptoms.
IBS has become one of the most commonly diagnosed gastrointestinal conditions around the world. And while there are differences in prevalence amongst various demographics, it can affect people of all ages and walks of life. So, it may be tempting to conclude that IBS is the only answer to what’s going on inside your gut.
But what if IBS is only one piece of the puzzle? Research now suggests that up to 60–70% of IBS cases may be linked to Small Intestinal Bacterial Overgrowth (SIBO)—a treatable condition that could be the key to finally relieving your symptoms and improving your quality of life.
So, let’s take a closer look at IBS, SIBO and the connections between the two.
Understanding IBS: The Gut Struggle is Real
You’ve probably seen commercials that talk about IBS during a football game or while watching your favorite shows. TIME Magazine even ran an article recently entitled “Why Does Everyone Seem to Have IBS Now?” While this is an overstatement, it does feel like IBS is popping up everywhere.
So what is IBS? IBS is a functional gastrointestinal disorder characterized by abdominal pain, bloating, and altered bowel habits, which may include diarrhea, constipation, or a combination of both. Unlike structural disorders like Crohn’s disease or diverticulitis, IBS does not involve visible abnormalities in the gastrointestinal tract.
The disorder is often classified into subtypes based on the predominant bowel habit: IBS-D (diarrhea-predominant), IBS-C (constipation-predominant), and IBS-M (mixed).
Root Causes of IBS: The Origins of Your Symptoms
For many the exact cause of IBS remains unknown, with factors such as gut-brain axis dysregulation, food sensitivities, changes in the gut microbiome, and motility issues (meaning your digestion is moving too quickly or too slowly) possibly playing a role.
However, for some IBS sufferers, a cause can be specifically identified. Emerging research now indicates that IBS can be the result of food poisoning. Doctors call this Post-Infectious IBS or PI-IBS. It’s estimated that 1 in 9 cases of IBS—and possibly as many as 60% of cases classified as IBS-D—can be linked back to a foodborne gastric infection. Gemelli Biotech has developed an easy at-home test for this type of Post-Infectious IBS, and there are focused courses of treatment that can help those whose results are positive. For more information, check out this article on PI-IBS.
The Silent Invader: How SIBO Takes Over Your Small Intestine
SIBO or Small Intestinal Bacterial Overgrowth is a condition characterized by an abnormal increase in the number and type of bacteria in the small intestine. Normally, the small intestine contains relatively few bacteria compared to the large intestine (colon). However, with SIBO, bacteria from the colon migrate and take up residence in the small intestine, leading to an overgrowth.
This overgrowth of bacteria can disrupt normal digestive processes, leading to uncomfortable and debilitating symptoms such as bloating, abdominal pain, nausea, diarrhea, constipation, and malabsorption of nutrients. If left untreated, prolonged vitamin and mineral deficiencies caused by this malabsorption can even damage bones and the nervous system.
While most people have at least heard of IBS, SIBO has largely flown under the radar outside of medical and scientific circles. However, within the gastroenterological community, SIBO is the subject of an immense amount of study, which has resulted in some important breakthroughs in our understanding of this condition. One of the most notable of these breakthroughs is the discovery that there is a much stronger correlation between SIBO and IBS (and other types of GI dysfunction) than previously thought. To understand this relationship, let’s take a closer look at what causes SIBO.
Causes of SIBO: The "Broken Dishwasher" Effect
There are many potential causes of SIBO, including complications from abdominal surgery, structural problems or blockages in the small intestine, Crohn’s disease, scleroderma, celiac disease, diabetes, and IBS. The reality is that anything that disrupts the normal motility and function of the gut could potentially lead to SIBO, especially if left undiagnosed or untreated for prolonged periods.
The Microbiome Connection, a highly regarded guide to IBS & SIBO co-authored by Dr. Mark Pimentel, Executive Director of the Medically Associated Science and Technology (MAST) Program at Cedars-Sinai and Dr. Ali Rezaie, Medical Director of the GI Motility Program at Cedars-Sinai, offers an excellent explanation:
“Any factor that slows down the speed of flow [of food] through the small intestine has the potential to cause [bacterial] overgrowth…
Imagine that you turn on your dishwasher before you go to bed, but one of the cycles isn’t working. When you open the dishwasher in the morning, you find food stuck on your cups and plates, which has allowed bacteria to grow on them. You pull the dishes out anyway and eat breakfast on them. This is, in effect, what happens if undigestible food is allowed to fester in your gut overnight. The undigested food just sits in your gut and can breed bacteria.”
In this analogy, your gut is like the dishwasher, performing a similar function of cleaning out food particles so they don’t linger and become harmful to your body. When your gut is behaving normally, it pushes food through your digestive system in “cleaning waves” approximately every 90 to 120 minutes when you aren’t eating. These waves strip out debris in the gut after a meal and keep the environment clean.
But if you’re experiencing factors like IBS, that are slowing down these cleaning waves or creating a situation where this natural cycle has become erratic, this may cause food to sit in your gut, creating a feeding ground for bacteria to feast and rapidly reproduce, thus leading to SIBO.
Can I Have Both IBS and SIBO?
The short answer is a resounding YES.
As we’ve discussed, many conditions that disrupt your gut’s natural motility or allow bacteria to exist in excessive numbers can lead to SIBO. And emerging research suggests that IBS, which can cause so much chaos with your digestive health, has a high degree of correlation with bacterial overgrowth because the typical functions that prevent that overgrowth are disrupted.
Additionally, current theories suggest that IBS sufferers may be more inclined to present with SIBO because of abnormalities in what has been termed the “gut-brain connection”. The gut-brain connection is a bidirectional communication system linking the GI tract and the central nervous system through neural pathways, hormones, and biochemical signals, including those from the gut microbiota. It is now believed that IBS interferes with this connection, which in turn dysregulates the healthy cleaning functions of the gut.
“The thought is that episodes of pain, bloating, changes in stool frequency and consistency in IBS are related to the way the brain and GI tract communicate with each other,” says Elizabeth Schaefer, MD, a pediatric gastroenterologist at Ascension St. Vincent and Peyton Manning Children’s Hospital in Indianapolis. Since people with IBS often have overactive or hypersensitive nerves in the GI tract, this can result in abnormal GI tract motility.
While the exact percentage of patients with IBS who are also diagnosed with SIBO varies depending on a number of factors (such as type of IBS, gender, diet, and geography) controlled studies show that the prevalence of SIBO is measurably higher in patients with IBS than those without. And Dr. Pimentel reports that recent data indicate that up to 60% to 70% of patients with IBS may also have SIBO. This is especially true of patients who have been diagnosed with IBS-C or whose symptoms include chronic constipation, but SIBO can be indicated in all types of IBS.
Your Next Step: Testing for Bacterial Overgrowth
One of the most difficult aspects of diagnosing patients with IBS, SIBO, and other gut problems is that so many of these conditions and diseases share similar symptoms, most commonly abdominal pain, bloating, diarrhea, and constipation. If you’ve been suffering from any or all of these symptoms for some time, it’s likely that you have experienced firsthand the difficulty of trying to obtain a specific diagnosis. So, what should you do next?
While tests are not currently available to accurately diagnose every kind of GI condition, fortunately, there is an easy at-home test to help identify patients with SIBO: The Trio-Smart 3-Gas Breath Test. This test allows you to collect samples of your breath and then send it to Gemelli Biotech’s laboratory for processing. The laboratory measures the amount of each gas in your sample and provides you with a report of the measured levels of each of these gases. These results can help your healthcare provider decide whether a SIBO diagnosis is appropriate and then develop a personalized treatment plan that works best for you.
How does this work? Scientists know that bacteria in your gut produce three specific gases that can help you figure out what’s going on in there: hydrogen, methane, and hydrogen sulfide. Excess levels of one or more of these gases could indicate the presence of bacterial overgrowth in your system, and the type of gas present has shown to be a reliable predictor of which type of IBS or IBS-like symptoms you are experiencing. Diarrhea (IBS-D) typically correlates with hydrogen and hydrogen sulfide, whereas constipation (IBS-C) typically correlates with methane. Furthermore, recent studies have revealed that the more excessive each of these gases is, the more severe your correlated symptoms are likely to be.
Why Does It Matter?
Your gut health journey can be overwhelming and exhausting. It may be tempting at times to give up or—if you’ve already received a diagnosis of one condition—to stop your search for more answers. But the more information and test results you have in-hand, the higher the likelihood that you will finally get the relief that you deserve.
Breakthroughs in treatment and condition management are offering new hope for patients suffering from IBS and bacterial overgrowth, and doctors are now finding that certain methods work better for certain problems, or combinations of problems. Specific courses of antibiotics like Rifaximin and other pharmaceuticals, dietary changes, and lifestyle modifications can be tailored by your healthcare team to fit the exact cause or causes of your distress. So, it’s in your best interest to find out everything you can about what’s going on inside your gut, and determining whether or not you have SIBO is an integral part of this journey.
References:
https://gi.org/topics/irritable-bowel-syndrome/#tabs3
https://time.com/7020813/do-i-have-ibs/
https://www.youtube.com/watch?v=vrJbsfAe0xI
https://my.clevelandclinic.org/health/diseases/21820-small-intestinal-bacterial-overgrowth-sibo
The Microbiome Connection: Your Guide to IBS, SIBO, and Low-Fermentation Eating, page 78
https://my.clevelandclinic.org/health/body/the-gut-brain-connection