Irritable bowel syndrome (IBS): Causes, symptoms, treatment, risk factors 

A range of disorders can affect the stomach and intestines, and IBS is one of them. Learn more about this condition and how it can affect a person.

A woman experiencing nausea due to IBS while eating rice and sauce

Key takeaways:

  • Irritable bowel syndrome (IBS) is a chronic health condition with discomforting gastrointestinal symptoms. While people with IBS find it challenging to live with, there are medications and treatment options that can help ease the symptoms and improve their quality of life.
  • IBS has no permanent cure at the moment. But medications, lifestyle, and dietary changes can go a long way in managing the symptoms.
  • If left untreated in some cases, IBS can lead to complications such as malnutrition and hemorrhoids.

Sometimes, it is hard to tell exactly why a person is experiencing some abdominal discomfort. Such is the case with irritable bowel syndrome (IBS). This condition is characterized by various gastrointestinal symptoms, including cramping, diarrhea, and altered bowel movements, with no exact known cause.

Even though health experts are uncertain about what causes IBS, many people have this condition. It is one of the most commonly diagnosed gastroenterological diseases. About 7–16% of Americans have IBS, and according to a 2021 study, it is most common in young people and people assigned female at birth.

In this article, we will discuss IBS, its symptoms, causes, and treatment. We will also review the potential complications and risk factors for IBS.

What is irritable bowel syndrome?

Irritable bowel syndrome (IBS) is an uncomfortable but common gastrointestinal disorder. It is a collection of symptoms that affect the digestive system. Although IBS is typically a lifelong condition, the symptoms may vary over time.

However, IBS has little impact on some people's physical health. The condition also does not enhance the chances of developing intestinal cancer or other intestinal-related problems.

 Irritable bowel symptoms could also be called irritable bowel, spastic colon, irritable colon, or nervous stomach.

People with IBS often have irregular bowel movements. Some days, everything feels okay, and other days, they may experience changes in their bowel movement. The type of bowel movement experienced shows the type of IBS you have:

  • IBS with constipation (IBS-C): this type makes your stool lumpy and hard. A person with this type of IBS will experience constipation and less frequent bowel movements accompanied by abdominal discomforts.
  • IBS with mixed bowel habits (IBS-D): This type makes your stool loose and watery on the same day. It causes frequent bowel movements and is often accompanied by abdominal pain and discomfort.
  • IBS with mixed bowel habits (IBS-M): The "M" here stands for mixed. This type makes your stool both hard and watery on the same day. This is characterized by alternating constipation and diarrhea.

Cause of irritable bowel syndrome

The exact cause of IBS is still unknown, and healthcare professionals believe many things can cause the syndrome. They may determine the cause of each person's condition based on the symptoms they are experiencing.

Healthcare experts believe some possible causes of IBS include:

  • Intestinal muscle contraction: The intestine walls are lined with muscle layers that contract as food moves through the digestive tract. When contraction lasts longer and is stronger, it usually leads to bloating, gas release, and diarrhea. Also, weak contraction slows the passage of food and can lead to dry hard poop.
  • Nervous system issues: Problems with the nerves in the digestive system can cause discomfort when the abdomen stretches to release gas or poop. When the signal between the brain and the intestine is poorly coordinated, it can cause the body to overreact to normal digestive processes. This can lead to constipation, pain, or diarrhea.
  • Severe infection: Irritable bowel syndrome may develop after a severe occurrence of diarrhea caused by a virus or bacteria. This is known as gastroenteritis. 
  • Early life stress: Individuals exposed to difficult life events, particularly in their early life, are likely to experience IBS.  This is because early life stress can induce different gastrointestinal impairments. Scientists are not sure how childhood stress causes this, but a study reported by Asia Research News suggests this is because stressful events in childhood could trigger the release of a protein called nerve growth factor which can cause high serotonin levels. When the levels of serotonin in the body are high, it can lead to IBS symptoms.
  • Food sensitivities or intolerance: Eating certain foods can cause some people to experience digestive problems.

Symptoms of irritable bowel syndrome

Symptoms of irritable bowel syndrome may differ from person to person. It also ranges from mild to severe, although most people experience mild symptoms. Health experts often diagnose IBS when a person is experiencing the symptoms at least three times a month for three consecutive months or more. The major symptoms of IBS include:

  • Abdominal cramps or pain, usually in the lower part of the abdomen.
  • Bowel movements that are looser or harder than usual.
  • Bloating
  • Constipation, diarrhea, or alternating between the two
  • Mucus in the stool (sometimes whitish)
  • Excess gas

These symptoms are not always persistent. They may disappear for a while, only to recur after some time. Symptoms like gas and bloating always go away after a bowel movement, while others may continue occurring.

If you have IBS with constipation (IBS-C), you will find it difficult to pass stool often—you may only pass a small amount or none at all.

If you have IBS with diarrhea (IBS-D), you may experience frequent watery, loose stool. It may also be difficult to control the urgent need for a bowel movement.

Some people with IBS experience loss of appetite. People with vaginas who have IBS usually find the symptoms more severe during their period. People with these symptoms find it difficult to perform their daily activities as it comes with very discomforting stress.

How to diagnose IBS

The easiest way to diagnose IBS is through the symptoms. There is no particular test carried out for this disease. One is said to have IBS after a thorough physical and history examination following a proper understanding of the symptoms already experienced. Also, doctors may conduct some tests to rule out other issues as possible causes of the symptoms.

  • Blood test. This test helps check for other health conditions besides IBS, such as digestive disease, infection, and anemia.
  • Stool test. This helps to check for blood in the stool or any other signs of disease or infection. Doctors may also check for blood in stool by physically examining the rectum.

IBS treatment

Just as there is no specific test for IBS, there is also no current standard treatment for it. Treatment is only targeted to relieve the symptoms. And sometimes, healthcare professionals may suggest some home remedies to help manage the condition. The following home remedies will help relieve the symptoms:

  • Regular physical exercise
  • Avoid caffeinated beverages
  • Reduce stress
  • Take probiotics
  • Avoid spices or deep-fried food
  • Do not eat too much

Medications for IBS

If home remedies, such as dietary or lifestyle changes, do not provide relief, your doctor may prescribe medications to help relieve the symptoms. Some medications that may help improve IBS include:

  • Anti-constipation drugs
  • Antibiotics
  • Antidepressants and drugs to control muscle spasms.

Risk factor for irritable bowel syndrome

People with IBS experience digestive system symptoms occasionally in varying degrees of severity. However, there are factors that can increase the risk of developing these conditions, including:

  • Age. IBS is a common disorder that can occur at any age. Studies have mixed reports regarding its prevalence across all ages. While one study reports that it’s more predominant among young people aged 20-30 years, other studies report that it is 25% less common among people aged 50 years and above. According to a 2014 study, this could be because the symptoms resolve over time.
  • Gender. People assigned female at birth are likelier to have IBS than those assigned male. The female-male ratio for the condition is 2-2.5:1.
  • Genetics. A genetic change also promotes the risk of IBS. How this change enhances the risk of IBS is still unclear, but an individual is likely to develop IBS if a family member has it. Living in the same environment as someone with this condition may indicate that you are more likely to have it too.
  • Depression or anxiety. People with depression or anxiety are more likely to develop IBS. On the other hand, anyone with IBS is also likely to develop depression and anxiety.
  • History of childhood abuse or difficulty. Survivors of childhood sexual or physical abuse are at a greater risk of developing IBS.
  • Severe parasitic or bacterial gastroenteritis. Severe gastroenteritis can cause persistent IBS.

Some other risk factors for IBS include; food tolerance, exposure to antibiotics, somatic system disorder, and smoking.

Complications of irritable bowel syndrome

Even though some diets and lifestyle modifications can help manage IBS, it can still affect the quality of life. This can be stressful and difficult to deal with. The complications can affect the patient emotionally, physically, and also mentally.

Poor quality of life

IBS can meddle and reduce the quality of a person's life, making it challenging to perform certain daily tasks outside their homes, especially where access to the restroom is uncertain. Most patients would prefer to remain at home because of the complications.

Mood disorder

People with IBS are at risk of developing depression and anxiety. They are most likely to experience sad moods, insomnia, and fatigue. They may easily lose interest in their friends and hobbies, experience changes in their eating style, and may also have thoughts of suicide.

Sleeping disturbances

People with IBS usually experience sleeping problems, as cramps and abdominal pains may force them to stay awake at night. This experience can cause them to get easily tired during the day, with little or no strength.


Patients with IBS are usually dehydrated. This happens when the IBS is associated with a chronic disorder, and the patient does not take in enough water and electrolytes.


Malnutrition is common in patients with IBS. It is possible because some patients avoid foods that are nutritious in a bid to prevent IBS from worsening. For instance, some healthy foods such as wheat, rye, legumes, and some fruits may increase the symptoms of IBS, and cutting them out of your diet will reduce your nutritional sources.


This may be caused by problems associated with IBS, such as diarrhea, constipation, and straining during a bowel movement. It is common in patients with IBS, and it's usually not painful but causes bleeding during bowel movements.

Wrap up

IBS is a group of symptoms that affect the gastrointestinal tract. The symptoms include bloating, diarrhea, constipation, and cramping. Because clinicians cannot tell the exact cause of IBS, diagnosing it can be challenging. Still, they try to determine if someone has IBS by doing tests that rule out other things that could be causing the signs and symptoms.

IBS can be managed using medications and lifestyle modifications. If you experience persistent gastrointestinal problems, you should speak with a doctor for a proper diagnosis. If the diagnosis indicates you have IBS, your healthcare team will get you started on a personalized treatment plan based on your symptoms and their severity.


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