Exploring the Relationship Between IBS and Nausea: What You Need to Know

Irritable bowel syndrome (IBS) is a gastrointestinal (GI) disorder that presents with symptoms such as abdominal pain, gas, diarrhea, and constipation. The cause of IBS isn’t well understood, and it’s often correlated with stress or oversensitive nerves in the GI tract. Some people with IBS will also experience nausea, but it is less common than other symptoms.

This article explains IBS-driven nausea, its causes, and how to manage it.

Does IBS Cause Nausea?

IBS has been shown to cause nausea in some people. A report published by the International Foundation for Gastrointestinal Disorders found that less than 40% of people with the stomach disorder will experience IBS-related nausea at some point.  

Some people with IBS may experience delayed gastric emptying, otherwise known as gastroparesis, which occurs when the food in your stomach enters your small intestine slower than normal, or it stops entering the small intestine altogether.

Gastroparesis can often occur alongside IBS and is known to cause nausea.

What Causes Nausea in IBS?

IBS may not directly cause nausea. However, comorbid (coexisting) conditions that often go hand-in-hand with having IBS may cause nausea.

For example, many people with IBS also experience indigestion or have another condition known as gastroesophageal reflux disease (GERD). Nausea is a common symptom in both indigestion and GERD, and thus, people with IBS experiencing this symptom may have another disorder that contributes to their discomfort.

Other conditions that cause nausea in people with IBS are:

• Anxiety and depression
• Chronic fatigue syndrome
• Migraine headaches
• Dyspepsia (indigestion)

Certain medications taken for IBS or other disorders may also drive IBS-related nausea. One such medication is lubiprostone (Amitiza), which is used for treating constipation and disorders that cause constipation.

Oversensitive nerves, otherwise known as visceral hypersensitivity, is a commonly related condition to IBS that can cause symptoms like nausea. It develops when a person’s pain threshold in their internal organs is lower than that of people in the general population.

Another possible cause is compromised gut motility, which occurs when food movement through the GI tract is negatively affected. This, along with the previously mentioned conditions and causes, can all lead to IBS-driven nausea.

Managing and Treating Nausea in IBS

Since there is no cure for IBS, managing and treating IBS-related nausea requires various approaches, depending on the person and any overlapping conditions they may have.

Common treatments for IBS include:

• Probiotics
• Antibiotics
• Histamine-receptor antagonists
• Psychotherapy
• Peripheral opioid agonists
• Bile acid sequestrants
• Bulking agents
• Osmotic laxatives

Some therapies that can help to reduce nausea are:

Antinausea medications, such as dimenhydrinate (Gravol) or prochlorperazine (Compazine)

• Ginger or peppermint tea
• Neuromodulator medications, such as tricyclic antidepressants, gabapentin, benzodiazepines, and cannabinoids

Managing stress is another technique that can help to curb feelings of nausea in people with IBS. Some stress techniques include:

• Deep breathing
• Stretches
• Meditation
• Exercise regularly
• Eating a diet rich in whole foods
• Getting enough sleep
• Avoiding things that can worsen stress, such as alcohol, tobacco, and other substances

Related Conditions

Other disorders that may also develop or overlap with IBS include:

• Celiac disease
• Inflammatory bowel disease (IBD)
• Fibromyalgia (chronic pain condition)
• Interstitial cystitis
• Chronic pelvic pain
• Temporomandibular syndrome (TMJ)
• Gastroparesis

These disorders are not defined by nausea as a symptom, but they can all lead to it in some cases. For example, people with fibromyalgia may develop nausea by being in pain, whereas people with TMJ may experience nausea driven by headaches and dizziness.

Other disorders that may or may not be related to IBS can also cause nausea that feels similar. Some possible conditions include:

• Brain abscess
• Bowel obstructions
• Cholecystitis
• Cyclic vomiting syndrome
• Eating disorders
• Heart disease
• Hemorrhages
  
• Hepatitis
• Infections of the ear, stomach, or whole body
  
• Labyrinthitis
  
• Meningitis
• Motion sickness
• Peptic ulcers
  
• Seizure disorders
• Tumors
  

Some medications also can cause nausea. They include:

• Cancer drugs, such as chemotherapy and radiation
• Heart disease medications
• Medications used to treat diabetes
• Antibiotics
• Antivirals
• Gastrointestinal drugs, including Azulfidine (sulfasalazine) and Azasan (azathioprine)
• Certain narcotics
• Drugs used to treat Parkinson's disease

When to Contact a Healthcare Provider

Oftentimes, people with IBS can treat nausea at home, but if it persists or worsens, see a healthcare provider. Since nausea can lead to vomiting and can co-occur with the common IBS symptom of diarrhea, leaving it alone could potentially lead to dehydration, which could become severe.

To ensure a proper diagnosis, discuss all your symptoms with a medical provider, even if they don't seem to relate to IBS. In addition, inform the provider of your health history and of all the medications, vitamins, and supplements you take.

Summary

Nausea doesn't affect everyone with IBS, but it is common in as many as 40% of those with the condition. The nausea people experience with IBS is typically related to other disorders that coexist with IBS, making it challenging to pinpoint an exact cause.

There sometimes is trial-and-error in treating nausea with IBS. What works for one person may not work for another, and treatment requires an individualized approach.