IBS or IBD: How to Tell the Difference

People often confuse irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). Both are common illnesses that affect the gut, have similar symptoms and affect a person's quality-of-life. But IBS and IBD are very different, despite their almost identical acronyms. The disease process, the damage it can wreak on your body, and the long-term outcomes can vary greatly. In fact, one can be life-threatening if it isn't treated early.

Understanding the differences between IBD and IBS is important for an accurate diagnosis and effective treatment plan. If you think you might have one or both (yes, they can occur together) of these conditions, here's what you need to know.

Understanding IBS

IBS is the most common disease diagnosed by gastroenterologists. It's also one of the most common disorders seen by primary care physicians, according to the American College of Gastroenterology.

IBS is a disorder of how the gastrointestinal (GI) tract works. It can take many forms, including IBS-C (causing constipation), IBS-D (causing diarrhea) or IBS-M (a mix of constipation and diarrhea). IBS is difficult to detect, which can be frustrating for individuals who struggle with the discomfort of daily symptoms.

"The GI tract may move too fast, causing diarrhea. Or it may move too slowly, causing constipation," says gastroenterologist Florence Aslinia, MD, at The University of Kansas Health System.

In addition to diarrhea and constipation, other signs that suggest IBS include:

  • Abdominal pain, bloating, gas
  • Normal appearance of colon
  • Normal lab tests with no inflammatory markers
  • A family history of IBS

Diagnosing and treating IBS

Blood tests and a thorough understanding of your medical history and symptoms are the most common ways IBS is diagnosed. Still, physicians aren't sure what causes it. But they do know stress and certain foods can trigger flare-ups. To manage symptoms, Dr. Aslinia prescribes a 3-step plan:

  • Change your diet. Eliminate gluten and dairy and eat a low-FODMAP diet (foods that cause gas, bloating and possibly diarrhea).
  • Add fiber. Take a fiber powder supplement and drink plenty of water.
  • Reduce stress. Eliminate the stress you can. Learn to better manage the stress you can't. Meditation and regular exercise can help ease symptoms.

Dr. Aslinia notes there are other medical options for IBS, such as an FDA-approved antibiotic that helps those with IBS-D. For those with IBS-C, some antidepressants can help, too.

If diarrhea persists longer than 6 weeks despite managing stress and improving diets, see a primary care physician

IBS vs. IBD

IBS vs. IBD
see how these conditions are similar and what makes them different.

Understanding IBD

Unlike IBS, IBD is a disease of chronic inflammation in various areas of the GI tract. IBD is actually an umbrella term for conditions that cause GI inflammation, including ulcerative colitis, Crohn's disease, celiac disease and microscopic colitis. IBD can be serious, and if left untreated, it can become life-threatening.

More than 3 million U.S. adults may have IBD – nearly triple the number of previous estimates, according to a 2016 estimate by the Centers for Disease Control and Prevention.

"We are not sure if the cause is stressful lifestyles, processed foods, sugar and fat, antibiotic use, exposure to chemicals or because we just do a better job diagnosing those patients," Dr. Aslinia says. "But we do know it involves a hyper immune system."

Hyper immune systems have an exaggerated reaction to certain foods, bacteria, viruses or chemicals. The overreaction causes inflammation in the bowel that can lead to alarming symptoms, such as:

  • Constipation
  • 5 loose bowel movements a day for 6 weeks or longer
  • Bowel movements in the middle of the night
  • Rectal bleeding
  • Unintentional weight loss
  • Fever
  • Moderate to severe abdominal pain

Diagnosing and treating IBD

If not detected and treated early, IBD can cause bowel perforations, fistulas, cancer or growth retardation in children.

"Diagnose early, start treatment and stay on it to avoid life-threatening problems down the road," Dr. Aslinia says.

Locating where the inflammation is in the GI tract will help physicians determine which type of IBD is present. Gastroenterologists typically use a test such as colonoscopy, CT scan, MRI, endoscopy or enteroscopy to locate the inflammation.

If IBD is confirmed, medications can help manage symptoms. But IBD is a chronic illness, which means there is no cure. A combination of medical treatments and lifestyle changes, such as the 3-step plan Dr. Aslinia recommends for IBS, can help keep symptoms under control.

Map showing the location of The University of Kansas Hospital Indian Creek Campus.

Comprehensive care for IBD

We recently opened the first and only multidisciplinary inflammatory bowel disease program in Kansas. Located in Overland Park, the program staffs multiple gastroenterologists, 3 colorectal surgeons, nutritionists, a psychologist, a group of specialized radiologists, a pathologist, a pharmacy and an infusion center. "We have everything patients need under one roof," Dr. Aslinia says.
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