It’s easy to think SIBO and IBS are just two names for the same condition, but they’re actually quite different. Many of our clients at Plenish come in believing they’re dealing with SIBO when it turns out to be IBS—and vice versa. Understanding what’s really going on in your body is so important because it allows you to follow a personalized nutrition approach that can truly ease your symptoms and help you feel like yourself again.
We wanted to create this guide to walk you through the most common symptoms of IBS and SIBO, highlight the main differences between the two, and give you a better idea of how working with an experienced nutritionist can support you on your journey toward better gut health.
What is the Difference Between SIBO and IBS?
The main difference between SIBO (Small Intestinal Bacterial Overgrowth) and IBS (Irritable Bowel Syndrome) is that SIBO is a specific, often diagnosed condition caused by an overgrowth of bacteria in the small intestine. Whereas IBS (Irritable Bowel Syndrome) is the name given to a bunch of gut symptoms that don’t have an obvious explanation.
Here’s a breakdown of some of the other differences between SIBO and IBS:
Location of the symptoms
SIBO is found in the small intestine, whereas IBS can typically affect the entire digestive tract.
Nutrient Deficiencies
SIBO can often cause the malabsorption of certain nutrients, for example, Vitamin B12 or Iron; this is not common in IBS.
Symptoms
SIBO often causes a severe, sometimes immediate feeling of bloating and or swelling of the stomach, whereas IBS symptoms are frequently pain-predominant.
Diagnosis
SIBO can be diagnosed with a breath test, and although it’s not always effective, it is the most commonly used. There isn’t a specific test used to diagnose IBS, but tests for other conditions might be done to rule them out; for this reason, IBS is more commonly diagnosed through exclusion of other conditions.
Although they share similar symptoms, SIBO tends to be a treatable condition– and in many cases, it might actually be the root cause of your IBS.
SIBO Symptoms
To better understand this condition, let’s look at the symptoms often associated with SIBO (Small Intestinal Bacterial Overgrowth):
- Nausea
- Gas
- Fatigue
- Diarrhea
- Malnutrition
- Constipation
- Abdominal pain
- Loss of appetite
- Bloating and Abdominal distention
- Unintentional Weight Loss
- An uncomfortable feeling of fullness after eating
These are some of the most common symptoms you might experience if you are suffering from SIBO. Below are the key signs to look for; if you recognize these symptoms, we recommend you visit your doctor to discuss the possibility of SIBO:
- Persistent diarrhea
- Rapid, unintentional weight loss
- Abdominal pain lasting more than a few days
If you have severe abdominal pain, it is important to seek professional help as soon as possible.
IBS Symptoms
Although SIBO and IBS share many common symptoms, we want to highlight those that set them apart. If you are dealing with IBS, you are likely to experience the following symptoms:
- Belly pain
- Increased gas
- Changes in the appearance of stool
- Sensation of incomplete evacuation
- Changes in how often you pass stool
- Cramping or bloating that is related to passing stool
It is important to be aware of the following symptoms, so you know when to reach out to your doctor for a formal diagnosis:
- Weight loss
- Rectal Bleeding
- Diarrhea at night
- Unexplained vomiting
- Iron deficiency anemia
- Pain that isn’t relieved by passing gas or stool
While it’s clear that these two conditions have a lot in common, getting a professional opinion is key to figuring out whether you’re dealing with SIBO or IBS.
How Working with a Nutritionist Can Help with SIBO or IBS
There are many ways a SIBO/IBS nutritionist can support you in managing your symptoms. Your nutritionist will help you uncover what you’re experiencing – whether it’s IBS or SIBO so you can have clarity on what you’re dealing with. Before choosing who to work with, it’s really important to make sure they have experience specifically with SIBO or IBS.
During a consult call, don’t be afraid to ask about this. It can also be helpful to ask for examples of past clients they’ve supported, so you can get a better feel for their approach and how they might be able to support you.
Here’s what it looks like to work with a SIBO / IBS nutritionist:
Create a personalized nutrition plan
Based on your unique needs and whether you’re dealing with IBS, SIBO, or both, a nutritionist may recommend approaches like a low-FODMAP diet, a SIBO-specific food guide, or, in some cases, an elemental diet to help reduce symptoms and support gut balance.
Provide treatment support and guidance
You’ll be guided through appropriate treatment options, which may include antibiotics or herbal antimicrobials specifically for SIBO.
Manage symptoms through targeted nutrition
You will receive support in easing common symptoms like bloating, gas, abdominal pain, and motility issues with nutrition tailored to either IBS or SIBO.
Guide you through the food reintroduction process
You’ll be supported in safely reintroducing foods after restriction phases, helping you identify personal triggers, ensure you’re meeting your nutritional needs, and avoid long-term unnecessary restriction.
Support your long-term gut healing
You will learn which supplements and strategies may help repair your gut lining and support your motility.
Conduct a comprehensive lifestyle assessment
Your nutritionist will look at your overall lifestyle, including eating habits, stress levels, and meal timing, so you can support better digestion, motility, and long-term gut health.
Ready to Work With a SIBO/ IBS Nutritionist?
Hopefully, this helped clarify for you the main differences between SIBO (Small Intestinal Bacterial Overgrowth) and IBS (Irritable Bowel Syndrome), and that you can now take steps towards easing your symptoms.
At Plenish, we cut through the noise with science-based nutrition support that’s sustainable and realistic. No cookie-cutter solutions here. We help you stay nourished, manage your SIBO or IBS symptoms, and care for your body.
Our dietitians specialize in using functional nutrition to help ease your symptoms. All of our practitioners are Licensed Dietitian-Nutritionists (LDNs), Certified Nutrition Specialists (CNS), and Registered Dietitians (RDs and they each hold a master ’s-level degree in nutrition.
Want to learn more about working with us? You can go here to book your complimentary call with us or go here to learn more about our services.
Psst… don’t forget to grab our FREE Nutrition 101 Guide! This free guide blends functional medicine and intuitive eating to help you support your hormones, digestion, and energy through consistent, compassionate nourishment.
With this guide you’ll learn how to:
- Create structure that supports, not restricts
- Understand the link between your nutrition, mood, and metabolism
- Build habits that feel calm, sustainable, and evidence-based
