What Is the Difference Between Irritable Bowel Syndrome (IBS) and Inflammatory Bowel Disease (IBD)? 

Irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) are two chronic gastrointestinal disorders that share some overlapping symptoms, like abdominal pain, bloating, and diarrhea. 

While IBS and IBD have similar symptoms and acronyms, they are two distinct conditions with different underlying causes and treatment approaches. IBS is a functional disorder, meaning it affects how the intestines work but doesn't cause inflammation. IBD is an inflammatory disease that damages the gastrointestinal (GI) tract. 

In the United States, IBS affects between 25-45 million people, and IBD affects more than 3 million people.

Symptoms of IBS vs. IBD

Both IBS and IBD affect the GI tract and cause uncomfortable symptoms and changes in bowel habits that can disrupt daily life. People with either condition may experience abdominal pain, cramping, and diarrhea. It's common for symptoms to come and go in both IBS and IBD, with periods when symptoms go away (remission) before they return (flare-ups).

While it's common to get the two confused, IBS and IBD affect the GI tract in different ways, and each causes distinctive symptoms that can range from mild to severe.

Differences

Recognizing the differences in irritable bowel syndrome and inflammatory bowel disease is essential for accurate diagnosis and effective treatment.

IBD Is an Inflammatory Disease

IBD is a chronic inflammatory condition that affects the GI tract. Over time, inflammation damages the intestines. IBD includes ulcerative colitis and Crohn's disease, both of which can lead to complications, such as bowel obstruction, ulcers (open sores) in the intestines, infection, and malnutrition. Inflammation associated with IBD also increases the risk of colon cancer. 

IBS is a functional GI condition that causes problems with the digestive system's function but is not associated with inflammation and does not cause visible damage to the GI tract. 

Healthcare Providers Use Different Diagnostic Processes

There is no specific test to diagnose IBS, so healthcare providers typically diagnose it based on symptoms and a detailed medical history review. To receive an IBS diagnosis, you must have IBS symptoms for at least six months and abdominal pain associated with bowel movements at least one day a week, along with changes in the frequency or appearance of your bowel movements.

To diagnose IBD, healthcare providers use diagnostic tests, such as computed tomography (CT) and magnetic resonance imaging (MRI) scans or colonoscopy, to identify inflammation in the GI tract and confirm the type of IBD you have (such as Crohn's disease or ulcerative colitis). Blood and stool tests can also help check for inflammation markers in the blood or stool of people with IBD. 

People With IBD Have More Chronic Diseases

People with IBD are more likely to have or develop other chronic conditions, such as cardiovascular disease, lung disease, arthritis, cancer, liver disease, and migraine. An estimated 81% of people with IBD have another chronic disease. The increased risk of other conditions is likely due to inflammation associated with IBD, which may be systemic (bodywide) and affect more than just the GI tract.

People with IBS are more likely to experience other functional disorders, such as fibromyalgia, chronic fatigue syndrome, chronic pelvic pain, and temporomandibular joint disorder (TMJ). Researchers are working to identify the connection between IBS and other functional disorders. Some evidence suggests that changes in how the brain and gut communicate may play a role, and certain genetic and lifestyle factors may contribute to the development of these disorders. 

The Treatment Options for IBS and IBD Aren't the Same

There is no cure for IBS or IBD, and treatment approaches are vastly different for each condition. 

IBS treatment focuses on relieving symptoms and often involves dietary changes, stress management, and different medications to control specific symptoms, such as anti-diarrheal medicines for diarrhea, laxatives for constipation, and antispasmodic or anti-depressant drugs for pain management.

IBD treatment aims to reduce inflammation and prevent symptom flare-ups and damage to the GI tract. Treatments may include anti-inflammatory medications, immunomodulators, and biologic drugs. In some cases, surgery may be required to remove damaged sections of the intestine. Because it can lead to serious complications, IBD generally requires more regular monitoring than IBS.

Similarities

Despite their fundamental differences, IBS and IBD have some similarities—both conditions can impact quality of life, share potential symptom triggers, and require dietary management. 

IBS and IBD Both Affect Quality of Life 

Both IBS and IBD can have a profound impact on your quality of life. The unpredictable and sometimes debilitating symptoms can disrupt daily activities and interfere with your ability to work, go to school, travel, or socialize.

On top of chronic GI pain, people with either condition may experience anxiety about potential flare-ups and the need to plan life around bathroom access, which can lead to social isolation, depression, and a lower quality of life.

Stress Can Trigger Symptom Flares With IBS and IBD 

Psychological factors like stress and anxiety are well-known triggers for symptom flare-ups in both IBS and IBD. Research suggests the gut-brain axis—a complex network linking the brain and the GI tract—plays a role in how stress affects these conditions. Stress can change the way the gut and brain communicate and alter the sensitivity and function of the digestive system, triggering the onset of flare-ups or worsening of IBS or IBD symptoms.

Similarly, stress can worsen inflammation in people with IBD and trigger symptom flare-ups or more severe symptoms. Stress management techniques, such as meditation and regular physical activity, are important for living well with IBS or IBD.

Both IBS and IBD Require Dietary Modifications 

Dietary modifications play an essential role in managing both IBS and IBD to help relieve or control symptoms. With IBS, nutritional adjustments may involve identifying and eliminating trigger foods that worsen symptoms, eating more fiber, and following a low-FODMAP diet.

With IBD, dietary changes may include avoiding certain foods that worsen gut inflammation or following a specific diet, such as an anti-inflammatory or Mediterranean diet.

While the dietary needs vary from person to person, people with IBS or IBD can generally benefit from a balanced diet rich in fruits, vegetables, and lean protein while limiting processed, fried, and greasy foods.

Can You Have Both IBS and IBD?

Yes, it is possible to have both IBS and IBD. Some people with IBD may experience IBS symptoms, particularly when IBD is well-controlled (in remission). Researchers believe there may be several explanations for why this happens:

• IBD-related inflammation may damage nerves in the gut or make the gut more sensitive, leading to changes in gut function even in the absence of inflammation. 
• Disruptions to the gut microbiome, the community of microorganisms that live in the gut, may trigger IBS symptoms in people with IBD. 
• The stress and anxiety of living with a chronic inflammatory condition like IBD can trigger IBS symptoms like abdominal pain and diarrhea even when IBD is in remission. 

To diagnose IBS in people with IBD, healthcare providers use a standardized set of criteria known as the Rome criteria. These criteria help distinguish between different types of gastrointestinal disorders. Although there can be some overlap between the symptoms of IBD in remission and IBS, using these criteria helps healthcare providers make a more accurate diagnosis and develop appropriate treatment plans.

When To Seek Care and Who to Contact

See a healthcare provider if you experience persistent or severe symptoms of IBS or IBD, including: 

• Abdominal pain or cramping 
• Bloody stools
• Excessive gas or bloating
• Frequent diarrhea, constipation, or both 
• Unintentional weight loss 
• Fever

If you've not already under the care of a GI specialist (gastroenterologist), your first point of contact should be your primary care physician. They can review your symptoms and medical history and may order initial diagnostic tests or refer you to a gastroenterologist if they suspect IBS or IBD.

A gastroenterologist is a doctor specializing in diagnosing and treating conditions affecting the gastrointestinal system. They can perform specialized tests, such as an endoscopy or colonoscopy, to diagnose the cause of your symptoms and recommend the appropriate treatment. 

Your PCP may refer you to a specific gastroenterologist in your area based on your health insurance plan, or you may choose to find a GI specialist on your own. Some hospitals and organizations have online directories where you can search for specialists by location, and some insurance providers have search tools to find an in-network provider.

A couple of trustworthy directories you can use include the American College of Gastroenterology's Find a Gastroenterologist tool and the Crohn's & Colitis Foundation's Find a Medical Expert.

A Quick Review

Irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) are two gastrointestinal conditions that share some symptoms, such as diarrhea and abdominal pain. However, they are distinct conditions and require different treatment approaches. IBS is a functional disorder that does not damage the intestines, while IBD involves chronic inflammation that damages the gastrointestinal tract. 

Despite their differences, both IBS and IBD can affect your quality of life and require treatment and lifestyle modifications. See a healthcare provider if you experience persistent or severe digestive issues like abdominal pain, bloody stools, frequent diarrhea, or constipation. Early diagnosis and treatment can control symptoms and help people with IBS and IBD live well.