Inflammatory bowel diseases (IBDs) like IBS are the third-most common digestive diseases in the world, affecting an estimated 4.9 million people. Though less understood, another increasingly prevalent digestive condition is SIBO. SIBO can be diagnosed alone or with other conditions, especially IBS. Understanding the symptoms of SIBO vs. IBS can help explain how these conditions are linked and why a diagnosis for one may indicate the other. Are you confused about your uncomfortable digestive system symptoms and wondering if they mean SIBO, IBS, or both? This guide will explain the most important things to know.
What Is SIBO?
SIBO (small intestinal bacterial overgrowth) features a collection of digestive symptoms caused by an overgrowth of harmful bacteria in the small intestine. SIBO can occur on its own, but it is also a common side effect of IBS.
There are three types of SIBO, each with its own unique set of symptoms:
- Hydrogen SIBO: Features symptoms like bloating, stomach pain, diarrhea, and, rarely, dehydration or malnutrition
- Methane SIBO: Features constipation as the primary symptom, though diarrhea is also possible
- Hydrogen Sulfide SIBO: Features symptoms like excessive gas, stomach pain, diarrhea, and if left untreated, nervous system effects
SIBO is often a side effect of other conditions. As mentioned, one of them is IBS. Other digestive conditions that may lead someone to develop SIBO symptoms include celiac disease, Crohn’s disease, diabetes, and enteritis.
What Causes SIBO?
Inefficient digestion causes SIBO in most cases, though genetics, overuse of antibiotics, and pre-existing medical conditions are also risk factors.
Someone’s digestive system can stop performing optimally for many reasons. Two of them are overstressed organs of the gastrointestinal tract. The GI system can become stressed for many reasons, including hypertoxicity.
Hypertoxicity happens when the body is exposed to a high amount of environmental toxins, antibiotics, and other contaminants.
What Is IBS?
IBS (irritable bowel syndrome) is a condition that affects the large intestine, resulting in digestive symptoms that can reduce someone’s quality of life. These symptoms are often chronic, meaning they reoccur over time.
Like SIBO, IBS symptoms can be divided into categories, each with its own symptomatology:
- Constipation-dominant IBS: Features constipation, gas, bloating, stomach pain, incomplete evacuation, and nausea
- Diarrhea-dominant IBS: Features diarrhea, fatigue, and malnutrition
- Mixed IBS: Features alternating episodes of diarrhea and constipation as the primary symptom
- Unclassified IBS: Features symptoms that don’t qualify someone for any other IBS subtype
Due to their ability to interrupt someone’s daily life, all four types of IBS can also come with mental health symptoms like anxiety and depression. People with constipation-dominant IBS are at high risk for these symptoms.
What Causes IBS?
IBS has no known cause, though an overgrowth of bacteria in the intestines is the most likely culprit. Risk factors include genetics, pre-existing mental health conditions, and certain food allergies.
Symptoms of SIBO vs. IBS
SIBO and IBS share many of the same symptoms. Specifically, they have virtually identical effects on the gastrointestinal system: constipation, diarrhea, bloating, gas, stomach pain, and nausea.
However, there are also important differences to understand. For instance, SIBO can impact the nervous system but is not associated with mental health symptoms like IBS.
Hydrogen sulfide SIBO may lead to tingling in the extremities and sensitivity to light or sound. Meanwhile, IBS is tied to mood and stress disorders, especially when associated with constipation-dominant IBS.
The Relationship Between IBS and SIBO: ‘Which Came First, the Chicken or the Egg?’
IBS can be symptomatic of SIBO. However, the reverse may also be true. 78% of people with IBS end up with a SIBO diagnosis; only 40% of people who do not have IBS get SIBO.
How are IBS and SIBO connected? Here are two leading theories to explain the bi-directional link between these two conditions.
When IBS Leads to SIBO
SIBO may result from dysmotility. Dysmotility is the slowed movement of food and waste through the small intestine. This theory may explain why SIBO is more prevalent in people with constipation-dominant IBS, wherein dysmotility is a primary symptom.
When food and waste get backed up in the small intestine, stool remains in the colon. Bacteria may migrate from the colon back to the small intestine and multiply, resulting in an overgrowth.
When SIBO Leads to IBS
Another theory scientists are looking into is SIBO’s effect on the gut microbiome. The gut microbiome is the collection of bacteria and other organisms that help with food digestion. SIBO-related changes to the microbiome may increase one’s risk of developing IBS symptoms. Emerging research has backed this theory. Researchers have found that treating dysbiosis, or an imbalanced gut microbiome, may reverse IBS symptoms.
Diagnosing SIBO and IBS
Another major distinction between IBS and SIBO is that SIBO can be diagnosed. Breath tests can identify which subtype of SIBO is causing someone’s symptoms.
Diagnosing IBS is not so clear-cut. However, when it’s caused by SIBO, diagnosing SIBO can help someone better understand their symptoms.
Traditional SIBO tests identify levels of gases produced by gut bacteria. These gases correspond with the SIBO subtypes: hydrogen, methane, and hydrogen sulphide. A positive SIBO breath test may increase the chances of an IBS diagnosis.
At Revolution Gut Health, we use a different strategy to understand digestive system conditions like SIBO and IBS. Our tests measure the level of environmental toxins running through someone’s system.
Since toxins are often responsible for inefficient digestion, high levels may correlate to SIBO, IBS, or both.
After receiving a diagnosis, individuals can customize a treatment to reduce levels of these toxins. The aim is to get the body’s natural detoxification pathways to function optimally and reduce SIBO and IBS symptoms.
Supporting SIBO and IBS With Revolution Gut Health
Regarding the symptoms of SIBO vs. IBS, these conditions share much in common. Many scientists believe this is because SIBO and IBS are linked, with SIBO causing IBS in some cases and IBS leading to SIBO in others.
Are your digestive symptoms ruining your life? Take your life back with Revolution Gut Health. Schedule a free consultation with one of our gut health experts to get tested or learn more about SIBO or IBS.