Updated on March 27, 2024.
Irritable bowel syndrome (IBS) is a chronic condition that affects the digestive tract. It is characterized by a group of symptoms that occur at the same time, including abdominal cramping and changes in bowel movements. Though IBS shares some symptoms with inflammatory bowel disease (IBD), the two are distinct conditions.
The exact cause of IBS is not known. But experts believe that gastrointestinal (GI) conditions like IBS may involve genetics, eating habits, psychological factors, and how the brain and gut, or GI tract, work together.
IBS can affect anyone, but it’s twice as likely to occur in women as in men, and it most often occurs in people younger than 50 years of age. Here’s what you need to know about addressing the condition.
There are different types of IBS
Irritable bowel syndrome can be classified into three categories, based on stool consistency. This classification helps healthcare providers (HCPs) accurately treat symptoms.
- IBS with constipation (IBS-C) is characterized by stool that's hard or lumpy at least 25 percent of the time and loose or watery less than 25 percent of the time.
- IBS with diarrhea (IBS-D) is characterized by stool that's loose or watery at least 25 percent of the time and hard or lumpy less than 25 percent of the time.
- IBS with mixed bowel habits (IBS-M) is characterized by bowel movements that consist of at least 25 percent hard or lumpy stool and at least 25 percent loose or watery stool.
Symptoms can vary
IBS doesn’t cause other health problems or damage the gastrointestinal tract, but it does have some uncomfortable symptoms. People with IBS often experience gas, bloating, abdominal pain or discomfort, and constipation or diarrhea (or both). They may also experience an urgent need to go to the bathroom and may notice white mucus in their stool.
It’s important to know that weight loss, bleeding, fever, and severe pain that does not go away are not symptoms of IBS. If you have these symptoms, talk to your HCP right away, as they may suggest other problems.
Causes are unclear
The causes of IBS are not fully understood and triggers vary among people. People with IBS often have other health problems, including:
- Digestive diseases, such as dyspepsia (indigestion) and gastroesophageal reflux disease (GERD)
- Conditions involving chronic pain, such as chronic fatigue syndrome, chronic pelvic pain, and fibromyalgia
- Certain mental health disorders, such as anxiety or depression
Diagnosis can be difficult
There is no single test for diagnosing IBS. Your HCP will likely assess your symptoms, review your medical history, and perform a physical exam. You may receive a diagnosis of IBS if you have pain in your abdomen, plus two or more of these symptoms:
- Pain that improves or worsens after you have bowel movements
- Changes in how often you have bowel movements
- Changes in the way your stools look
Your HCP will also consider the duration of your symptoms in making a diagnosis. You may have IBS if you’ve had symptoms at least once a week over the previous 3 months and your symptoms began at least 6 months ago.
It may be necessary for your HCP to order tests to rule out other conditions. You may need a blood test or a biopsy to check for celiac disease or a stool culture test to look for a potential infection. You might also be advised to get a colonoscopy to check for cancer. This is particularly the case if you are over the age of 45, if you experience sudden and unexplained weight loss, or if you have bloody stool or an abnormal blood test.
Dietary changes may help
The goal in treating IBS is to eliminate the symptoms. Treatments aren’t one-size-fits-all and individuals may need to manage symptoms with a combination of methods.
Fiber-rich diets can help alleviate diarrhea and constipation but may increase bloating. There are two main types of fiber:
- Soluble fiber dissolves in water and is found in oats and many fruits and vegetables.
- Insoluble fiber does not dissolve in water and is found in seeds, whole grains, and root vegetables.
Beans contain both soluble and insoluble fiber. Depending on the type of bean and the way the beans are prepared, they may be tolerated by people with IBS.
Research suggests that eating soluble fiber for IBS may be best, since it's more helpful than insoluble fiber in relieving symptoms. The American College of Gastroenterology recommends soluble fiber to treat IBS symptoms, but not insoluble fiber.
Consult with your HCP before adding foods with fiber to your diet. When you do, it’s advisable to add them slowly, in increments of 2 to 3 grams per day, to prevent bloating and gas.
Some people may benefit from adopting what’s known as a low-FODMAP diet. FODMAPs (also known as fermentable oligo-, di-, monosaccharides, and polyols) are gas-producing carbohydrates that are often hard to digest. High-FODMAP foods include:
- Vegetables and legumes such as asparagus, beans, cabbage, cauliflower, garlic, mushrooms, and onions
- Fruits such as apples, apricots, cherries, pears, plums, and watermelon (or juices made from these fruits)
- Dairy products such as milk, soft cheeses, yogurt, custard, and ice cream
- Foods that contain wheat or rye
- Honey and foods with high-fructose corn syrup
- Products containing sweeteners with names that end in “-ol” (such as sorbitol, mannitol, and xylitol)
- Canned fruit that comes in natural fruit juice, as well as large amounts of dried fruit
The low-FODMAP diet is not a list of foods to avoid completely. Instead, your HCP may advise that you eliminate foods that are high in FODMAPs, then re-introduce them one by one to determine what is best for your diet. Note that getting enough dietary fiber can be challenging on a low-FODMAP diet, so it’s important to consult with your HCP before trying this strategy.
Some people with IBS may also have more symptoms after eating gluten, a protein found in wheat, barley, and rye. Your HCP may recommend that you avoid foods that contain gluten.
Caffeine is also a potential trigger for IBS, so you may be advised to you limit your intake of coffee, tea, soda, and energy drinks.
There is some evidence that probiotics may help improve IBS symptoms in some patients. Your HCP can advise whether taking probiotics is right for you, and if so, what dosage makes sense.
Reducing stress may help as well
Strong emotions, such as those arising from stress, anxiety, depression, and fear, may trigger or worsen a bout of IBS.
Your HCP may suggest you try mental health therapies to help relieve IBS symptoms. These may include cognitive behavioral therapy (CBT), relaxation training, or hypnotherapy (hypnosis).
Lifestyle changes that reduce stress—like seeking social support and establishing better sleep habits—can also help manage symptoms. Exercise is well-known to relieve stress, as well. In the case of IBS, working out may also improve symptoms and help food move through the GI tract.
If lifestyle approaches don’t improve your condition, your HCP may suggest you take over-the-counter or prescription medications to manage IBS.
