Few things are worse than the discomfort and confusion associated with an IBS diagnosis. If you are reading this blog post about diagnosing IBS while you scroll on your phone from the toilet, you likely know what I mean.
Are you less interested in the details and just want to take the “Do I have IBS?” quiz?
For those wanting all the details about diagnosing IBS, keep reading…
Table of Contents
- IBS is a diagnosis of exclusion
- Signs and symptoms of IBS
- How to diagnose IBS
- Diagnostic procedures used when diagnosing IBS
- Laboratory tests to identify the root cause of your IBS
- SIBO Breath Test
- Stool Testing with Microbiome Assessment
- IBS Smart
- Mediator Release Food Sensitivity Test
IBS is a diagnosis of exclusion
An IBS diagnosis can be challenging to work with because IBS, which stands for Irritable Bowel Syndrome, is a diagnosis of exclusion. That means the answer to the question “how to diagnose IBS” is first to rule out all other gastrointestinal issues.
The diagnosis comes only after excluding every other gastrointestinal condition because there is no currently accepted biological marker (meaning something that you can measure in someone’s blood or stool) that confirms a diagnosis of IBS. And yet, as more research is being done, there are many biological markers we can utilize to put us on the right track for treatment (more on this later).
Signs and symptoms of IBS
There are many poor gut health symptoms associated with IBS. A few of the most common signs and symptoms are:
- Abdominal pain and cramping, also known as visceral hypersensitivity.
- Bloating (the uncomfortable sensation of trapped gas and abdominal pressure).
- Abdominal distension and protrusion: An example of this is suddenly looking pregnant after eating.
- Excessive flatulence (a fancy way to say passing gas).
- Diarrhea with or without feeling like you have to go urgently.
- Constipation with or without straining.
How to diagnose IBS
First, your healthcare practitioner will start with a complete medical history, physical exam, and blood work to rule out other conditions such as Celiac Disease, Inflammatory Bowel Disease, and cancer. They may also perform other tests and diagnostic procedures if your symptoms indicate the need.
Diagnostic procedures used when diagnosing IBS:
- Endoscopy. An endoscopy may be recommended if conditions such as Celiac Disease or a hiatal hernia are suspected. A camera on the end of the tube lets your doctor view your upper digestive tract from your esophagus to your small intestine.
- Colonoscopy. This test provides live video images of the colon and rectum. It enables the doctor to examine the intestinal lining for inflammation, ulcers, polyps, and other signs of more serious gastrointestinal conditions.
- CT scan. This test is more commonly used with severe abdominal pain. It produces images of your abdomen and pelvis to help rule out appendicitis and structural abnormalities.
You’ve been diagnosed with IBS; now what?
After ruling out these more serious conditions, most people are diagnosed with IBS and provided little support beyond the recommendation to follow a low FODMAP diet and offered a prescription for a pharmaceutical to manage their symptoms, which is a travesty given the tools and resources available.
This is where functional laboratory testing comes into play and is crucial for identifying the root cause of your IBS symptoms so you can stop using bandaids like restrictive diets and medications to manage symptoms.
Laboratory tests to identify the root cause of your IBS
- Small Intestinal Bacterial Overgrowth (SIBO) Breath Testing
Three-hour hydrogen methane breath testing helps us to assess the rise in gases in the small and large intestines. Elevated hydrogen over 20 parts per million within the first 90 minutes indicates bacterial overgrowth of the small intestine.
Elevated hydrogen causes diarrhea and increased motility, while elevated methane causes constipation and decreased motility. Methane elevation can occur in the small or large intestine and is called intestinal methanogen overgrowth – it causes severe constipation.
When using breath testing, it is important to know that all of the substrates (lactulose, fructose, glucose) used can provide false negatives and that you may need to use more than one substrate for accurate assessment. You also will get more accurate results for methane with lactulose.
- Stool Testing with Microbiome Assessment
Stool testing gives insight into critical areas of digestive function, including digestion, absorption, and inflammation.
It also provides insight into the health of your gut microbiome and the metabolites it produces. The beneficial bacteria in your gut produce short-chain fatty acids that provide various health benefits, including weight loss and mood enhancement.
Through stool testing, we can identify what specific foods, probiotics, prebiotics, and selective antimicrobial herbs will benefit you most and create a tailored protocol to improve your digestive health. - IBS Smart
The IBS Smart test is ideal for those whose IBS was caused by food poisoning, giardia, traveler’s diarrhea, or some other bacterial gastroenteritis. This test measures antibodies anti-vinculin and anti-CdtB.
Elevated anti-CdtB levels indicate a recent case of gastroenteritis and that you may be more susceptible to subsequent gastroenteritis. Sidenote: Some probiotics protect against reinfection, which is very helpful for these individuals. See my probiotic guide for more details.
Elevations in anti-Vinculin indicate autoimmunity has developed, damaging gut function by disrupting nerve signaling of the migrating motor complex. The migrating motor complex is a recurring cyclic cleansing wave that keeps the small intestine clear of bacterial overgrowth and food debris. When it isn’t functioning correctly, bacterial overgrowth occurs.
The higher the level of anti-vinculin, the greater the risk of relapsing SIBO. Prokinetics, vagal toning exercises, and lion’s mane mushrooms are essential supports for restoring function to the migration motor complex and preventing relapsing SIBO.
- Mediator Release Food Sensitivity Testing
A word of caution about food sensitivity testing – many inaccurate tests are available – from hair testing to IgG. It’s important to understand the limitations of testing and also to be able to identify scientifically validated testing options.
Food sensitivities are a complex immune reaction involving multiple triggering mechanisms, which leads to the release of mediators from white blood cells that cause pain and inflammation. This is different from a food allergy. Food sensitivities exacerbate and worsen digestive symptoms and Irritable Bowel Syndrome.
The challenge in dealing with food sensitivities is that they are difficult to identify because the reaction is often delayed by hours to days. In many cases, multiple food and chemical sensitivities are making an elimination diet extremely challenging.
Significant relief of symptoms usually occurs within the first seven days of removing reactive foods. With time and an effective gut healing protocol, food sensitivities can often be reversed.
This is not an exhaustive list of the testing options available, but it highlights some of the most helpful tests for identifying the root cause of IBS symptoms. An IBS diagnosis doesn’t have to be a dead end. If you still aren’t sure you are dealing with IBS and feel stuck on what steps to take next, take the “Do I have IBS?” quiz right now.