Nausea From IBS: The What, the Why, and How to Treat It

Grace Clark-Hibbs

March 26, 2021

Feeling like you’re going to throw up every day and not sure why. Wondering if it’s connected to your IBS?

Well, it might be.

Keep reading to find out what’s going on internally and possible reasons why your nausea and IBS are connected. Plus, suggested treatments to get you feeling well again.

What is IBS?

First, let’s talk about irritable bowel syndrome, or IBS.

IBS is a functional gastrointestinal (GI) disorder – meaning the way the GI tract functions has been disrupted – and is defined as “abdominal pain or discomfort that occurs in association with altered bowel habits over a period of at least three months.” (1)

IBS is a common problem that affects about 20% of the world’s population and is more often seen in women. (2) In addition, symptoms usually start between the ages of 20-40 years of age. (3)

Can You Really Get Nausea From IBS?

Although nausea is not one of the most common symptoms in people suffering from IBS, it is often seen in those experiencing a mix of constipation and diarrhea, or IBS-M. (4) Nausea can be a debilitating symptom and can have a significant impact on your quality of life.

In most cases, the nausea is a secondary symptom that is experienced after the following: (5)

  • Feelings of early fullness
  • Bloating after eating
  • Abdominal pain

Feelings of early fullness, bloating and abdominal pain often occur soon after eating in people with IBS, which then can lead to nausea and possibly vomiting. In this situation, your IBS is likely causing the nausea. Ask yourself if these symptoms were triggered by a specific food. Frequent foods that trigger IBS symptoms include alcohol, dairy, coffee, or fatty/fried foods.

However, there is also the possibility that your IBS is overlapping with another functional GI disorder, such as:

  • Functional dyspepsia (FD)
  • Delayed gastric emptying
  • GERD (gastroesophageal reflux disorder)
  • Migraines

Let’s get into what each of these conditions are and how they influence your feelings of nausea.

Functional Dyspepsia

The symptoms listed above (early fullness, bloating and abdominal pain) are frequent markers of a condition known as functional dyspepsia (FD). (5) FD and IBS have many symptoms that overlap and are two of the most commonly diagnosed functional GI disorders, however in most cases they get diagnosed independently of each other. (6, 7)

The primary difference between these two conditions is that with functional dyspepsia there is no connection between the uncomfortable GI symptoms and altered bowel movements. This means that IBS does NOT explain why the symptoms are present and additional work needs to be done to identify the root cause. (6)

A few of the processes that have been suggested as root causes of functional dyspepsia include: (5, 6)

  • Slow GI motility
  • Hypersensitivity to bloating
  • A past infection (such as H. pylori)
  • Central nervous system disfunction

Let’s dive into the four processes listed above. When you have slow GI motility, food is not moving through you intestinal tract as quickly as intended. This can cause things to back up and often leads to bloating. Some people are more sensitive to the feeling of being bloated, which can cause discomfort and even nausea and/or vomiting.

Some infections, such as H. pylori (which is a bacteria that can cause stomach ulcers if left untreated), can also lead to stomach discomfort, pain and possibly nausea.

Lastly, the central nervous system, specifically the vagus nerve, plays a large role in how the gut functions. If the vagus nerve is not functioning correctly, it can lead to symptoms such as slow GI motility and hypersensitivity to bloating.

Delayed Gastric Emptying

Delayed gastric emptying is when the movement of food from the stomach to the small intestine either slows or completely stops even though there is no physical blockage. Research has shown that this occurs more often in women and usually leads to postprandial fullness (an uncomfortable feeling of fullness over a long period of time), nausea, and even vomiting. (8, 9)

Delayed gastric emptying is not thought to be the root cause of all symptoms of IBS or functional dyspepsia, but it often occurs in people with one or both of those conditions. (10)


Gastroesophageal reflux disorder (GERD) is another possible explanation for feelings of nausea. GERD is when the contents in the stomach re-enter the esophagus and cause uncomfortable symptoms, often referred to as heartburn. (11)

GERD is commonly called acid-reflux because the contents in our stomach are extremely acidic. Since other parts of our GI tract are not designed to handle that level of acidity, this reflux often leads to extreme burning in the chest and can also lead to nausea.

Moreover, research has shown a strong connection between IBS and GERD. (11, 12) In fact, one study found about 64% of their participants with IBS, also had GERD. (13)


GI issues have been shown to occur in many people who experience migraines. This is particularly true during a migraine attack, but it can also be true during the periods between attacks. On the flip side, research has also shown that 23-53% of IBS patients experience frequent headaches. (14)

The reasons for the connection between migraines and IBS are not fully understood. Some believe that the relationship between the gut and the brain, or the gut-brain axis (or connection), is the primary explanation. (14)

This is because your gut plays a big role in your body’s production of serotonin (aka the “happy neurotransmitter”). Most people know that serotonin plays a large role in mediating your happiness and optimism, but lesser known fact is that it also plays an important role in GI function. Meaning, when serotonin levels are out of balance, IBS and migraines (among other symptoms) become more common. (14)

Mentioning the gut-brain connection brings us to the next possible contributor to your IBS with nausea, and that is stress.


The gut-brain connection has become a hot topic in recent years because studies have shown a clear connection between gut activity and psychological symptoms, such as depression, anxiety, and stress. (5, 6, 7, 15)

What exactly is the gut-brain connection, you ask? Well, it refers to the biochemical signaling that takes place between the gut and the central nervous system (primarily through the vagus nerve) and is believed to at least play a role in how functional GI disorders are developed. (15)

Have you ever experienced butterflies in your stomach when you have a big presentation at work or you have to have a difficult conversation with your partner that you’ve been putting off for weeks? That’s a perfect example of brain-to-gut communication.

Or, think about the way your IBS symptoms make you feel emotionally or psychologically drained. Think about the anxiety you get when you decide to go out to lunch with a friend and you’re not sure if the restaurant will have something on the menu that doesn’t trigger your symptoms. These are all examples of how the mind and body are connected.

This connection is believed to be bi-directional, which means there is evidence to show that the brain can influence the gut and digestion AND the gut can influence mood, anxiety, and stress levels. (16) It’s important for you to find a healthcare professional who understands this so they can approach your treatment from both directions.

Description of 4 possible causes of nausea

Medications May Also Contribute to Your Nausea With IBS

Certain medications can also increase your risk of experiencing nausea. These medications include:

This is not an exhaustive list, but all of these medications have been shown to cause nausea in some situations. Consult your healthcare professional if you think a medication is the cause of your nausea and before making any changes to your medication routine.

Nausea Treatment/Management Options

Despite how common functional digestive issues are, it can be difficult for healthcare practitioners to know exactly how to treat these conditions. This is because most confirmed diagnostic criteria involves an invasive and expensive procedure that many people who suffer from these conditions are not able to do or don’t want to go through. (7)

This is why the Rome Diagnostic Criteria (currently on the IV version) was created. Rome IV criteria provides a framework for the healthcare provider to go through, helping them identify when certain characteristic symptoms are present while other “alarm features” are absent. Meaning, it helps the practitioner rule out diseases such as celiac disease, Crohn’s disease, etc. and identify which functional GI disorder best matches the current situation. (7, 17)

Aa treatment plan can be made once a diagnosis is identified. The key is to work with your healthcare professional to first identify the root cause of your nausea. Ask yourself the following questions:

  1. Is it triggered by certain foods, such as alcohol, dairy, coffee, fatty/fried foods?
    1. Or foods that naturally produce more gas, such as broccoli, cabbage, or legumes?
  2. Am I regularly taking one of the medications listed above?
  3. Do I also experience GERD (heartburn), migraines, feelings of uncomfortable fullness, and/or feelings of stress, anxiety, or depression?

Suggested supplements for symptom relief

  1. Peppermint oil (18)
  2. Ginger (19)
  3. Acupressure (20)
    • Specifically the PC6 point located 2-3 fingerbreadths up the arm from the wrist crease

Final Thoughts

Persistent and recurring nausea will have a negative impact on anyone’s quality of life. In general, the nausea is a symptom of an underlying issue rather than the issue itself. Therefore, treatment will depend on what that underlying issue is. Only after the root cause is identified can a treatment plan be developed.

Connect with an appropriate healthcare professional before altering your medications or making any drastic dietary changes.

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Grace sitting

Hi, I’m Grace! A registered dietitian and gut health expert based in Portland, OR, where I live with my husband and our orange tabby, Tony. As someone who has struggled with my own severe, chronic, and painful bloat and constipation for over 15 years, I understand what it’s like not to get the answers you’re looking for from conventional medical support. So I decided to take matters into my own hands and figure out what was going on for myself using a functional nutrition approach and identifying my root causes. This approach was a game changer for me and now I’m on a mission to share it with every other woman experiencing embarrassing gut issues. You are not alone!

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