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When it comes to the world of gastrointestinal diseases, you may hear a lot of acronyms, such as IBD and IBS. Inflammatory bowel disease (IBD) is a broad term that refers to chronic swelling (inflammation) of the intestines.

Inflammatory bowel disease is often confused with the non-inflammatory condition irritable bowel syndrome (IBS).

Although the two disorders share similar names and some of the same symptoms, they have distinct differences. Read on to learn about the key differences.

If you have symptoms of either or both, be sure to discuss your concerns with your doctor or a gastroenterologist.

IBD and IBS are distinctly different conditions. Still, a person who has been diagnosed with one may display symptoms of the other.

It’s also important to know that you can have both conditions at the same time. Both are considered chronic (ongoing) conditions.

Read on to learn what distinguishes IBD and IBS.


The two most common conditions that are classified as IBD are:

Another form of IBD, indeterminate colitis, is diagnosed when tests cannot at first distinguish which form of IBD it is.

Most cases of indeterminate colitis eventually evolve to a diagnosis of either Crohn’s disease or ulcerative colitis.

The most common form of IBD is ulcerative colitis.

It’s a lifelong condition that’s characterized by recurring episodes of inflammation in the mucosal layer of the colon. It commonly involves the rectum and may extend to involve other parts of the colon.

The other common form of IBD, Crohn’s disease, can affect any part of your gastrointestinal (GI) tract, from your mouth to your anus. You may feel a frequent need for bowel movements but often feel they’re incomplete.

Symptoms of Crohn’s disease may also include diarrhea, abdominal cramps, and fever.

No cure is currently available, but it can be managed with medication.


Irritable bowel syndrome (IBS) is a chronic functional disorder of the gastrointestinal tract characterized by chronic abdominal pain and altered bowel habits.

IBS has physical symptoms, but the causes aren’t currently well understood.

Researchers are looking into some potential causes such as food intolerances (such as fructose, lactose, sucrose, or gluten), a reaction from a previous infection, bacterial overgrowth, and stress.

More research is needed to fully understand the causes.

Sometimes, IBS symptoms are called mucous colitis or spastic colitis, but those names are technically incorrect. Colitis is an inflammation of the colon, whereas IBS does not cause inflammation.

People with IBS show no clinical signs of a disease and often have normal test results. Although both conditions can occur in anyone at any age, they seem to run in families.

More research is needed to fully understand it.

IBS is characterized by a combination of:

IBD can cause the same symptoms as IBS, as well as:

In addition to urgent bowel movements, IBS patients may experience a feeling of incomplete evacuation as well. They may experience pain across the entire abdomen but most often in either the lower right or lower left.

Some people with IBS also experience upper right side abdominal pain without any other symptoms.

IBS differs in the amount of stool produced. IBS can cause loose stools, but the volume will actually fall within the normal limits. (Diarrhea is defined by volume, not necessarily by consistency.)

Depending upon the main symptom, people with IBS are diagnosed as one of three classifications:

  • constipation-predominant
  • diarrhea-predominant
  • pain-predominant

Abdominal pain is a common symptom of both IBS and IBD. With IBD, you may experience pain in other parts of your body, too.

Read on to learn about the differences in IBS and IBD pain.


Abdominal pain is the most common symptom that people with IBS report. Research shows 3 out of 4 people with IBS report either continuous or frequent abdominal pain.

The pain is most often felt in the lower abdomen, though it can occur anywhere in the belly. Type and severity of pain varies, even within a single day. Types and locations of IBS pain often include:

  • Upper abdomen. This pain may get worse after eating and is often accompanied by bloating.
  • Middle abdomen. This pain centers in the belly area and is often felt as cramping.
  • Lower abdomen. This pain usually decreases after a bowel movement.

People with IBS report different types of pain, including:

  • cramping
  • sharp, or stabbing
  • aching
  • throbbing

Pain associated with IBS includes both visceral pain, meaning it originates in bodily organs, and functional pain, which does not have a known bodily source and is not accounted for by any test.

Because its symptoms involve functional pain, IBS is sometimes categorized as a centralized sensitivity syndrome (CSS). These are groups of conditions that involve a heightened experience of pain, as in fibromyalgia and chronic fatigue syndrome.


Abdominal pain is also a common symptom of IBD.

The Crohn’s and Colitis Foundation estimates that 50 to 70 percent of people with IBD report gastrointestinal (GI) pain when IBD first begins and, later, whenever the disease is active.

People also report pain associated with IBD in other parts of the body, such as:

  • painful joints
  • skin sensitivity
  • eye discomfort
  • oral sores
  • pain around the rectum

IBS is extremely common. In fact, the International Foundation for Functional Gastrointestinal Disorders estimates that it affects up to 15 percent of the population worldwide.

About 10 to 15 percent of people live with IBS symptoms globally. This is also the most common reason why patients seek out a gastroenterologist.

The Centers for Disease Control and Prevention (CDC) reported that in 2015, 3 million Americans, or 1.3 percent of the adult population, were diagnosed with IBD. This represented an increase of about 50 percent over 6 years before.

Diagnoses of IBS and IBD are very different.

IBD is diagnosed through a variety of tests, whereas IBS is diagnosed largely by exclusion, or ruling out other diseases and conditions.

Read on to learn about how diagnoses are made for IBS and IBD.


Doctors do not order tests to diagnose IBS, although they may use test results to rule out other conditions. Instead, an IBS diagnosis is usually made on the basis of:

  • medical history
  • family history
  • physical exam
  • symptoms
  • ruling out other conditions

The Rome IV criteria form is the basis for diagnosing IBS.

These criteria say a diagnosis be made only after a person has had symptoms at least 1 day per week over the last 3 months and having symptoms that began at least 6 months ago.

Since IBS symptoms primarily involve your bowel movements, a diagnosis takes this into account as well. The Rome IV criteria for an IBS diagnosis specify that two of the following conditions be met:

  • Your symptoms are related to defecation.
  • The frequency of your stool has changed.
  • The appearance of your stool has changed.

Often, an IBS diagnosis is made only after many other diseases and conditions are ruled out. Since testing for other conditions can be a lengthy process, your IBS diagnosis may sometimes take weeks or even months.


Diagnosis of IBD, unlike IBS, will require medical tests. These will probably include blood and stool tests as well as imaging of your upper and lower GI tract.

These tests will be used to diagnose IBD as well as rule out other medical conditions.

Your doctor may also refer you for endoscopic evaluations such as an esophagogastroscopy and colonoscopy to evaluate the severity and extent of inflammation. These involve inserting a small tube with a camera into either the esophagus or the rectum.

During these exams, your doctor will likely collect tissue to biopsy to help differentiate between different types of IBD.

Other tests may include:

The exact causes of IBS and IBD are not known. Genetics and family history are thought to play a part in both. Read on to learn about what factors can contribute to the onset of IBS and IBD.


The cause of IBS is not known for certain, but the following conditions are thought to increase your risk:

  • bacterial infections in the intestines or colon
  • food intolerances and sensitivities
  • genetics, with a family history of IBS
  • mood disorders, such as depression and anxiety


The exact cause of IBD is not known. It’s thought that the main trigger is an immune system that does not operate as it should. Researchers now think that IBD arises through a combination of:

  • genetics
  • environmental factors
  • the gut microbiota, or the microorganisms that live in the body

Normally, the immune system successfully limits the effects of harmful bacteria, viruses, and environmental toxins. In a person with IBD, the immune system falters, and inflammation develops in the GI tract.

Researchers also think genetics play a part in causing IBD. People with a family history of either ulcerative colitis or Crohn’s disease are at greater risk for developing these diseases, which are the two main kinds of IBD.

Stress is known to make all GI disorders feel worse. There is a lot of truth when we describe a reaction as “gut-wrenching.” Read on to learn about the very real effects stress can have on both IBS and IBD.


Since the inflammation of IBD is absent in people with IBS, it’s difficult for researchers to understand the precise causes of IBS. But they do know that IBS is almost always exacerbated by stress.

Stress reduction techniques may help decrease your IBS symptoms. Consider trying:


Research shows that stress may affect both the onset of IBD and the course of the disease. In particular, it may serve to aggravate the disease and contribute to the occurrence of flare-ups.

Stress may also intensify the mood disorders that sometimes arise in people living with the disease. Emotional disorders such as depression and anxiety are common among people with IBD, and stress can intensify their effects.

Both IBS and IBD can lead to complications, especially if left untreated. Read on to learn about possible complications of these two conditions.


Chronic diarrhea, which is sometimes a symptom of IBS, can lead to hemorrhoids. You are also at risk for becoming dehydrated if you do not replenish fluids lost in diarrhea.

Over the long term, IBS can also lead to nutritional deficiencies. Your doctor or a nutritionist can help you learn how to maintain a nutrient-dense diet.

If left untreated, IBS can lead to a lower quality of life in which you miss days of work and are reluctant to engage in activities for fear that pain may arise at an inconvenient time.

With frequent worrying about your symptoms, you might also develop mood disorders such as depression and anxiety.


Symptoms of IBD may escalate to conditions that require medical attention. Ulcerative colitis and Crohn’s disease, the two main forms of IBD, each have different potential complications.

For ulcerative colitis, complications might include a perforated bowel in which the chronic inflammation creates a hole in your bowel.

Another potential complication of ulcerative colitis is rapid enlargement of your colon, which is called a toxic megacolon. You might also develop severe diarrhea or rectal bleeding and pain.

Complications of Crohn’s disease can include:

  • abscesses
  • strictures, or intestinal blockages
  • perforated bowel
  • fistulas, abnormal connections that develop between tissues or body parts and need to be managed for potential infection
  • malabsorption of food, leading to malnutrition

These complications can occur quickly. If they do, they will need to seek immediate medical help.

Complications of IBD can also develop outside the GI tract. For example, disorders may develop in other parts of the body, including:

  • eyes
  • skin
  • kidney
  • liver
  • joints
  • bones

Treatments for IBS and IBD vary based on severity. While IBS often responds well to lifestyle changes and avoiding triggers, IBD treatment is typically more complex.


IBS may be treated with certain medications such as intestinal antispasmodics like hyoscyamine (Levsin) or dicyclomine (Bentyl).

Dietary and lifestyle changes seem to help the most. People with IBS should avoid aggravating their condition with fried and fatty foods and caffeinated beverages.


IBD treatment depends on the form diagnosed. The primary goal is treating and preventing inflammation that over time can damage the intestines. Common treatment options for IBD can include:

  • corticosteroids
  • 5-ASA drugs (aminosalicylates)
  • immunomodulators
  • biologics
  • surgery
  • dietary changes

Treatment for IBD can be complex, so your gastroenterologist can help you create the right treatment plan for your needs.

Natural remedies are often called complementary and alternative medicine (CAM). These are products or practices that can be used alongside traditional medicine.

People with IBS and IBD may use CAM methods to decrease frequency of flare-ups, handle pain, and improve quality of life. There is currently little medical evidence of their effectiveness, however.

Natural remedies and CAM methods might include:


Alternative treatments for IBS focus on lessening symptoms. Though, like with IBD, the medical evidence is still very limited. If you want to try any of these complementary practices, speak with your doctor first.


The first line of treatment for IBD is usually medication. Natural remedies should only supplement your existing treatment plan with your doctor’s permission and supervision, and may not be effective.

However, psychotherapy is said to be especially helpful, as the anxiety that IBD can trigger can make symptoms worse. Learning to calm mood disturbances can make your IBD symptoms calmer too.

Dietary management can be helpful. Avoiding trigger foods may especially help to manage your IBD symptoms.

IBD and IBS may seem to share similar symptoms, but they are two different conditions with very different treatment requirements.

With IBD, the goal is to reduce inflammation that causes symptoms. IBS, on the other hand, may not be treatable with medications because there’s not an identifiable bodily cause.

Research is ongoing in an effort to develop more effective treatments. There are ways to manage your symptoms so you can have a good quality of life.

A gastroenterologist can help determine your specific condition and offer the best treatment plan and resources to help you manage symptoms.