While Crohn’s disease and IBS both share similar symptoms, the two conditions are distinct with different causes, diagnostic criteria and treatments.
Crohn’s disease is a type of inflammatory bowel disease (IBD) that can affect different parts of the digestive tract and is often confused with the noninflammatory condition called irritable bowel syndrome (IBS). Although the two disorders share similar names and some of the same symptoms, they are distinct.
IBD is the term for a group of inflammatory conditions that affect the digestive tract, which include Crohn’s disease and ulcerative colitis. On the other hand, IBS mainly affects the lower gastrointestinal (GI) tract, which includes the large intestine. Although some signs and symptoms of Crohn’s disease and IBS overlap, both conditions have different causes and treatments.
Crohn’s disease
Crohn’s disease belongs to the broad spectrum of IBDs that may affect any part of the GI tract from the mouth to the anus, although it’s most often found at the end of the small intestine and the beginning of the colon (large bowel). In Crohn’s, the immune system mistakes food, bacteria or other materials in the GI tract for foreign substances and responds by sending white blood cells into the lining of the bowels. The result of the immune system’s attack is chronic inflammation.
Irritable bowel syndrome (IBS)
IBS is a chronic functional disorder of the GI tract characterized by chronic abdominal pain and altered bowel habits. In people with IBS, the colon muscle tends to contract more than those without the condition. These contractions cause cramps and pain. People with IBS also tend to have a lower pain tolerance and show no clinical signs of a disease, often having normal test results.
What are the signs and symptoms of IBS?
Irritable bowel syndrome (IBS) is characterized by a combination of the following:
- Abdominal pain
- Cramps
- Constipation
- Diarrhea
- Urgent bowel movements
- A feeling of incomplete evacuation
- Pain across the entire abdomen but mostly in the lower right or left
- Some people with IBS also experience pain in the upper right side of the abdomen without any other symptoms
What are the signs and symptoms of Crohn’s disease?
Crohn’s disease can cause the same symptoms as irritable bowel syndrome (IBS), along with the following:
- Eye inflammation
- Extreme fatigue
- Intestinal scarring
- Joint pain
- Malnutrition
- Rectal bleeding
- Weight loss
How are Crohn’s disease and IBS diagnosed?
Diagnosis of irritable bowel syndrome (IBS) and Crohn’s is different.
Crohn’s is diagnosed based on a variety of tests, whereas IBS is diagnosed largely by exclusion or ruling out other diseases and conditions.
IBS diagnosis is usually made based on:
- Medical history
- Family history
- Physical exam
- Symptoms
- Ruling out other conditions
Diagnosis of Crohn’s, unlike IBS, will require medical tests, such as:
- Blood and stool tests, as well as imaging of the upper and lower gastrointestinal (GI) tract.
- Endoscopic evaluations, such as esophagogastroscopy and colonoscopy, analyze the severity and extent of inflammation.
These tests will be used to diagnose IBD, as well as rule out other medical conditions.
How are Crohn’s disease and IBS treated?
Treatments for irritable bowel syndrome (IBS) and Crohn’s vary based on severity. Although IBS often responds well to lifestyle changes and avoiding triggers, irritable bowel disease (IBD) treatment is typically more complex.
- IBS may be treated with certain medications, such as intestinal antispasmodics (hyoscyamine or dicyclomine).
- Dietary and lifestyle changes seem to help the most. People with IBS should avoid aggravating their condition with fried fatty foods and caffeinated beverages.
In Crohn’s, the primary goal is treating and preventing inflammation that over time can damage the intestines. Common treatment options for Crohn’s disease can include:
- Corticosteroids
- 5-ASA drugs (aminosalicylates)
- Immunomodulators
- Biologics, such as infliximab and adalimumab
- Surgery
- Dietary changes
