Irritable Bowel Syndrome (IBS)

Overview

Irritable bowel syndrome (IBS) is a common digestive condition that causes repeated abdominal pain and changes in bowel movements over a long period of time that does not go away on its own. It is a group of symptoms that occur together, including repeated pain in the abdomen and changes in bowel movements, which may be diarrhea, constipation, or both. With irritable bowel syndrome, a person has these symptoms without any visible signs of damage or disease in the digestive tract. 

Irritable bowel syndrome is a functional gastrointestinal (GI) disorder — what doctors now call a disorder of gut-brain interaction. These disorders relate to problems with how the brain and gut work together. These problems can cause the gut to become more sensitive and change how the muscles in the bowel contract. A more sensitive gut may cause more abdominal pain and bloating, while changes in muscle contractions lead to diarrhea, constipation, or both.

Irritable bowel syndrome is the most commonly diagnosed chronic GI condition. Women are more likely than men to develop irritable bowel syndrome, and people younger than age 50 are more likely to develop irritable bowel syndrome than people older than age 50.

Irritable bowel syndrome is a chronic disorder, meaning it lasts a long time, often years. However, its symptoms may come and go.

Irritable Bowel Syndrome in Children

Irritable bowel syndrome also affects children. Like adults, children with irritable bowel syndrome experience repeated abdominal pain and changes in bowel movements without any visible signs of damage or disease in the digestive tract.

Related terms: Doctors once used several different names for irritable bowel syndrome, including colitis, mucous colitis, spastic colon, nervous colon, and spastic bowel.

Signs and Symptoms

Adults

The most common symptoms of irritable bowel syndrome are pain in the abdomen, often related to bowel movements, and changes in bowel movements. Those changes may be diarrhea, constipation, or both, depending on the type of irritable bowel syndrome.

Other symptoms may include:

• Bloating, the sensation of tightness, fullness or pressure in the abdomen that sometimes is accompanied by visible swelling of the abdomen
• The feeling of not having finished a bowel movement
• Whitish mucus in the stool

Women with irritable bowel syndrome often have more symptoms during their periods.

Men seek medical care for irritable bowel syndrome much less frequently than women possibly because their symptoms are less bothersome and more often have diarrhea as the main complaint.

Three types of irritable bowel syndrome have been defined based on different patterns of bowel movements for the purpose of providing guidelines for treatment and labeling of drugs Individuals may change from one pattern or another over time.

• Irritable bowel syndrome with constipation (IBS-C): On days with at least one abnormal bowel movement, more than a quarter of stools are hard or lumpy and fewer than a quarter are loose or watery.
• Irritable bowel syndrome with diarrhea (IBS-D): On days with at least one abnormal bowel movement, more than a quarter of stools are loose or watery and fewer than a quarter are hard or lumpy.
• Irritable bowel syndrome with mixed bowel habits (IBS-M): On days with at least one abnormal bowel movement, more than a quarter of stools are hard or lumpy and more than a quarter are loose or watery.

Many people with irritable bowel syndrome have normal bowel movements on some days and abnormal bowel movements on other days.

Children

In children with irritable bowel syndrome, the most common symptoms are abdominal pain, often related to bowel movements, and changes in bowel movements. Other symptoms in children may include the feeling of not having finished a bowel movement, mucus in the stool, and bloating.

Experts have defined four types of irritable bowel syndrome in children: These definitions are used as a guide to help choose the best treatments, but individuals often do not fit precisely into one category, and their symptoms may change over time. There is much less information available on IBS in children.

• IBS-C: More than a quarter of stools are hard or lumpy, and fewer than a quarter are loose or watery.
• IBS-D: More than a quarter of stools are loose or watery, and fewer than a quarter are hard or lumpy.
• IBS-M: More than a quarter of stools are hard or lumpy, and more than a quarter are loose or watery.
• IBS unsubtyped (IBS-U): Fewer than a quarter of stools are hard or lumpy, and fewer than a quarter are loose or watery.

Related Health Effects

People with irritable bowel syndrome sometimes have other health problems. These include:

• Chronic pain conditions, such as fibromyalgia, chronic fatigue syndrome, and chronic pelvic pain
• Digestive diseases, such as dyspepsia and gastroesophageal reflux disease
• Mental health conditions, such as anxiety, depression, and somatic symptom disorder

People with irritable bowel syndrome may also experience disability and reduced health-related quality of life.

Causes and Risk Factors

Doctors are not sure what causes irritable bowel syndrome. Experts think a combination of problems may lead to irritable bowel syndrome, and different factors may cause irritable bowel syndrome in different people.

GI disorders such as irritable bowel syndrome involve problems with brain-gut interaction — how the brain and gut work together. In some people with irritable bowel syndrome, food may move too slowly or too quickly through the digestive tract, causing changes in bowel movements. Some people with irritable bowel syndrome may feel pain when a normal amount of gas or stool is in the gut.

Problems that experts think may play a role in causing irritable bowel syndrome include:

• Previous bacterial infections in the digestive tract
• Stressful or difficult early life events, such as physical or sexual abuse
• Certain mental health conditions, such as depression, anxiety, and somatic symptom disorder
• Small intestinal bacterial overgrowth — an increase in the number or a change in the type of bacteria in the small intestine
• Food intolerances or sensitivities, in which certain foods cause digestive symptoms

Research suggests that genes may make some people more likely to develop irritable bowel syndrome.

Factors that increase the chance of developing irritable bowel syndrome include:

• Having a family member with irritable bowel syndrome
• A history of stressful or difficult life events, such as abuse, in childhood
• Having had a gastrointestinal infection
• Being a woman (women are up to two times more likely than men to develop irritable bowel syndrome)
• Being younger than age 50

In children, irritable bowel syndrome is more common in those who have a history of:

• Bacterial infections in the digestive tract
• Certain emotional or mental health problems, such as stress, depression, and anxiety
• Events during infancy or early childhood that cause pain or inflammation, such as allergies, infections, or surgery
• Experiencing child abuse
• Family members with irritable bowel syndrome

Changes in the microbiome, which are the bacteria in the digestive tract that help with digestion, may also play a role in children.

Diagnosis

Adults

To diagnose irritable bowel syndrome, doctors review symptoms, medical history, and family history, and perform a physical exam. In some cases, doctors may order tests to rule out other health problems.

A doctor may diagnose irritable bowel syndrome if a person has abdominal pain along with two or more of the following:

• Pain related to bowel movements (for example, pain that improves or gets worse after a bowel movement)
• A change in how often bowel movements occur
• A change in how stools look

A doctor may diagnose irritable bowel syndrome if symptoms have occurred at least once a week in the last three months and first started at least six months ago.

Certain symptoms are considered warning signs that there might be another health problem instead of irritable bowel syndrome. These include:

• Anemia
• Bleeding from the rectum
• Bloody stools or stools that are black and tarry
• Weight loss

The doctor will ask about:

• A family history of digestive diseases, such as celiac disease, colon cancer, or inflammatory bowel disease,
• Medicines the person takes
• Recent infections
• Stressful events related to the start of symptoms
• Diet
• History of other health problems more common in people with irritable bowel syndrome

During a physical exam, the doctor usually:

• Checks for abdominal bloating
• Listens to sounds within the abdomen using a stethoscope
• Taps on the abdomen to check for tenderness or pain

There are no specific tests to diagnose irritable bowel syndrome. However, a doctor may order some of the following to check for other health problems that could be similar to IBS:

• Blood test to check for conditions such as anemia, infection, and digestive diseases such as celiac disease
• Stool test to check for blood in the stool or other signs of infections or diseases
• Other tests, which may include:
  • An upper GI endoscopy with a biopsy checks for celiac disease.
  • A sigmoidoscopy or colonoscopy checks for conditions such as hemorrhoids, infections, inflammatory diseases, or cancer.
  • A hydrogen breath test checks for small intestinal bacterial overgrowth or problems digesting certain carbohydrates, such as lactose intolerance.

Children

To diagnose irritable bowel syndrome in children, doctors review symptoms, medical history, and family history, and perform a physical exam. A doctor may diagnose irritable bowel syndrome if a child has abdominal pain at least four days each month along with one or more of the following:

• Pain related to bowel movements
• A change in how often the child has a bowel movement
• A change in how the child’s stools look

Doctors may diagnose irritable bowel syndrome if the child has had symptoms for at least 2 months and the symptoms cannot be fully explained by another health problem.

Symptoms that may suggest another health problem in children include:

• Arthritis
• Bleeding from the rectum, bloody stools, or stools that are black and tarry
• Disease in the tissues around the rectum
• Nighttime diarrhea
• Persistent pain in the upper or lower right side of the abdomen
• Persistent vomiting
• Problems or pain when swallowing
• Unexplained fever
• Weight loss, slowed growth, or delayed puberty

Additional tests for children may include imaging tests such as abdominal ultrasound upper GI endoscopy with a biopsy, or colonoscopy.

Treatment and Management

Doctors may treat irritable bowel syndrome by recommending changes in diet and other lifestyle changes, medicines, probiotics, and mental health therapies. A person often may need to try a few treatments to find what works best.

Diet and Lifestyle Changes

Changes in diet may help treat irritable bowel syndrome symptoms. A doctor may recommend one of the following:

Fiber may improve constipation in irritable bowel syndrome because it makes stool soft and easier to pass. Two types of fiber are:

• Soluble fiber, found in beans, fruit, and oat products
• Insoluble fiber, found in whole-grain products and vegetables

Research suggests that soluble fiber is more helpful in relieving irritable bowel syndrome symptoms. Adding fiber to the diet slowly, by 2 to 3 grams a day, may help prevent gas and bloating.

A doctor may recommend avoiding foods that contain gluten (a protein found in wheat, barley, and rye) to see if irritable bowel syndrome symptoms improve. Some people with irritable bowel syndrome have more symptoms after eating gluten, even though they do not have celiac disease.

Caution: Blood tests to diagnose celiac disease are not reliable if a person has been on a gluten-free diet for a period of time.

A doctor may recommend a special diet called the low FODMAP diet, which reduces or avoids certain carbohydrates that are hard to digest. Examples of foods that contain FODMAPs include:

• Fruits such as apples, apricots, blackberries, cherries, mango, nectarines, pears, plums, and watermelon
• Vegetables such as artichokes, asparagus, beans, cabbage, cauliflower, garlic, lentils, mushrooms, onions, and sugar snap or snow peas
• Dairy products such as milk, soft cheese, yogurt, custard, and ice cream
• Wheat and rye products
• Honey and foods with high-fructose corn syrup
• Products with sweeteners ending in “-ol,” such as sorbitol, mannitol, xylitol, and maltitol

Research also suggests that other lifestyle changes may help irritable bowel syndrome symptoms, including:

• Increasing physical activity
• Reducing stressful life situations as much as possible
• Getting enough sleep

Medicines

For irritable bowel syndrome with diarrhea, a doctor may recommend:

• Loperamide
• Rifaximin, an antibiotic
• Eluxadoline
• Alosetron, which is prescribed only to women and comes with special warnings and precautions

For irritable bowel syndrome with constipation, a doctor may recommend:

• Fiber supplements, when increasing dietary fiber does not help
• Laxatives
• Lubiprostone
• Linaclotide
• Plecanatide

For abdominal pain, other medicines may help, including:

• Antispasmodics
• Antidepressants such as low doses of tricyclic antidepressants and selective serotonin reuptake inhibitors
• Coated peppermint oil capsules

For children, medicines a doctor may recommend include:

• Antidepressants
• Antispasmodics
• Coated peppermint oil capsules
• Fiber supplements

Do not give a child medicines to treat irritable bowel syndrome unless directed by the child’s doctor.

Probiotics

A doctor may recommend probiotics, live microorganisms, most often bacteria, that are similar to microorganisms normally found in the digestive tract. Researchers are still studying the use of probiotics to treat irritable bowel syndrome. Talk with a doctor before using probiotics or any other complementary or alternative medicines or practices.

It is not unusual for people with irritable bowel syndrome to have worsening symptoms with many of the remedies described above that work for some people. Trial and error are often needed to find the best treatment for individuals. Keeping a careful diary of diet, medicines and life events that occur with symptoms is helpful to find the best approach since most people find it very hard to remember all of this information. Some symptoms, such as stress and lower quality of life, may be the result of irritable bowel syndrome rather than the cause.

Mental Health Therapies

A doctor may recommend mental health therapies to help improve irritable bowel syndrome symptoms. Therapies used to treat irritable bowel syndrome include:

• Cognitive behavioral therapy, which focuses on helping change thought and behavior patterns to improve irritable bowel syndrome symptoms
• Gut-directed hypnotherapy, in which a therapist uses hypnosis, a trance-like state in which the person is relaxed or focused, to help improve irritable bowel syndrome symptoms
• Relaxation training, which can help relax muscles or reduce stress

For children, mental health therapies may improve irritable bowel syndrome symptoms, help children cope, and prevent symptoms from interfering with school and other activities.

Living With Irritable Bowel Syndrome

If you have irritable bowel syndrome, you may need to try a few treatments, including lifestyle changes, medicines, probiotics, and mental health therapies, to find what works best. Work with your healthcare provider to find the right plan.

If you are considering complementary health practices such as hypnotherapy or acupuncture, ask a trusted source, such as the healthcare provider who treats your irritable bowel syndrome or a nearby hospital, to recommend a practitioner. Find out about the training and experience of any practitioner you consider.

Keep in mind that some dietary supplements can interact with medicines or other dietary supplements and may contain ingredients not listed on the label. If you are pregnant, nursing, or considering a supplement for a child, talk with a healthcare provider first.

For children with irritable bowel syndrome, talk with the child’s doctor or dietitian before making changes to the child’s diet to manage irritable bowel syndrome symptoms. Research suggests that some children with irritable bowel syndrome may benefit from reducing the amount of FODMAPs (carbohydrates that are hard to digest) in their diet. Proper nutrition is important for growth and development, and trained professionals can help plan a well-balanced diet.

Find Clinical Trials

Clinical trials uncover better ways to prevent, diagnose, treat, and understand diseases and conditions. To ensure results apply to everyone, volunteers of all ages, sexes, and backgrounds, including both healthy individuals and those with specific medical conditions, are needed. Find clinical trials on IBS - irritable bowel syndrome.

Research Information

The National Institutes of Health (NIH) is the largest public funder of biomedical research in the world. NIH invests most of its budget in medical research seeking to enhance life and to reduce illness and disability. NIH-funded research has led to breakthroughs and new treatments helping people live longer, healthier lives, and building the research foundation that drives discovery.

NIH conducts and supports research into many diseases and conditions, including digestive diseases.

Researchers are currently studying many aspects of irritable bowel syndrome, including:

• The relationship between the colon microbiome and irritable bowel syndrome symptoms
• Genetic and neurological factors related to irritable bowel syndrome
• The development of irritable bowel syndrome after an acute gastrointestinal infection

For research on irritable bowel syndrome in children, researchers are studying:

• How the microbiome and diet affect irritable bowel syndrome symptoms
• The management of digestive disorders such as irritable bowel syndrome
• The relationship between chronic abdominal pain and intestinal inflammation

NIH-supported studies are also looking at:

• How the brain influences sensations in the gut, with the goal of identifying complementary approaches to treat brain behaviors linked to gut sensing dysfunction
• How the gut’s sense of touch works in health and in functional GI diseases including irritable bowel syndrome

Find NIH-funded research projects using NIH RePORTER, a searchable database of current and past research projects supported by NIH and other federal agencies.