Irritable bowel syndrome (IBS) is a group of symptoms that affect the gastrointestinal (GI) tract. Some people with IBS experience nausea, which may be due to indigestion, gastroesophageal reflux disease (GERD), or medication.

IBS occurs when a person has abdominal pain combined with diarrhea or constipation. IBS does not cause damage to the GI tract or lead to other health conditions.

According to the International Foundation for Gastrointestinal Disorders, around 4 out of 10 women and 3 out of 10 men with IBS report nausea.

This article reviews whether IBS causes nausea, possible underlying reasons a person may feel nausea, other symptoms, and more.

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People with IBS sometimes report feeling nauseous. Nausea is a feeling of sickness or discomfort in the stomach, which usually comes with the urge to vomit.

IBS and nausea often occur due to either a comorbid condition or as a side effect of a medication.

Several factors may cause nausea in people with IBS. We discuss this in further detail below.

Indigestion

When it occurs, a person may feel nausea, among other symptoms. These symptoms usually occur shortly after meals.

GERD

Another possible cause of nausea with IBS is GERD.

GERD occurs when stomach contents start to make their way back up the esophagus on a frequent basis, which can cause nausea.

IBS and GERD often co-occur. A 2019 study found that 66% of people with IBS also had GERD symptoms. However, more research is needed to understand the relationship between the two conditions.

Medication

Nausea may also occur as a side effect of medications doctors use to treat IBS, such as antibiotics and stimulant laxatives.

A doctor may prescribe antibiotics, such as rifaximin, to treat people diagnosed with IBS with diarrhea (IBS-D). It is unclear exactly how rifaximin prevents IBS-D symptoms, but a 2017 study noted that it might reduce bacterial byproducts and alter a person’s intestinal microbiota.

Less than 0.4% of people experience any side effects from rifaximin.

Healthcare professionals may prescribe prosecretory agents (secretagogues) to help to relieve IBS with constipation (IBS-C). These drugs increase movement and fluid secretion in the gastrointestinal tract. They can also cause nausea as a side effect.

Some common examples of prosecretory agents for IBS include:

If medication is the cause of nausea, a person may experience the symptom shortly after taking it.

IBS causes several potential symptoms based on the type an individual has. There are three types:

  • IBS with constipation (IBS-C): A person will have irregular bowel movements that tend toward constipation. Abdominal pain and bloating may also occur frequently.
  • IBS-D: An individual will have irregular bowel movements that tend toward diarrhea. Abdominal pain or cramping is also often present.
  • IBS with mixed bowel habits (IBS-M): A person has bowel movements that alternate between diarrhea and constipation. Abdominal pain or discomfort is frequent.

Other common symptoms of IBS can include:

There is no current cure for IBS. Treatment aims to eliminate or reduce symptoms associated with the condition.

A healthcare professional may recommend one or more of the following therapies to treat IBS:

If a person has another condition leading to nausea, a doctor will likely take steps to help treat the other condition.

Home remedies

People can also take steps at home to help with their IBS symptoms. These include:

Several conditions can cause nausea, including ones that those with IBS also have. Some common causes of nausea include:

A person should consult a doctor if they experience symptoms that may indicate IBS.

They should also consider contacting a doctor if they experience additional symptoms, such as nausea, following a diagnosis of IBS. This could indicate medication or another condition may be responsible.

To diagnose IBS, a doctor will likely:

  • ask about a person’s symptoms
  • review family and personal medical history
  • conduct a physical examination
  • order blood or other tests to help rule out other conditions

IBS does not always directly cause nausea. Other conditions that can co-occur with IBS, such as indigestion, may be responsible. In some cases, a person may experience nausea as a side effect of medication used to treat IBS.

IBS can cause several symptoms, including pain, diarrhea, and constipation. A healthcare professional will work on treating a person’s symptoms. A person can also take measures at home, such as reducing stress and getting regular exercise, to help alleviate symptoms.