IBD versus IBS: The difference is everything

The New York Times recently published two articles in a series about inflammatory bowel disease, or IBD, in hopes to destigmatize the disease, and to broadcast medical and surgical advancements that have worked to change how we conceptualize IBD. I applauded the Times for highlighting what can be a debilitating disease for the 1.4 million Americans who are afflicted with it, and thought: Finally! IBD is getting the attention it deserves.

Albeit a biased view from a gastroenterologist, but given the potential complications that this systemic inflammatory disease can cause, the praise was warranted. That was until I saw the capsule summary and Twitter blurb from @nytimeswell that read: “Treatment for irritable bowel disease has made great advances, with less disruptive surgery.” Whaaa?! I read it again. Yep — that’s what it read — “Irritable bowel disease,” instead of inflammatory bowel disease. Typo? Likely. Small editorial oversight? Probably. Golden opportunity to delineate the differences between irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD)? Absolutely.

Clearly, IBS, or irritable bowel syndrome, shares two of three letters in its acronym with IBD, or inflammatory bowel disease. However, it is crucial to understand the significant differences between the syndrome of irritable bowel, and the disease of inflammatory bowel. Irritable bowel syndrome (IBS), a functional gastrointestinal disorder that affects anywhere from 10-20% of the US population, is a much more common condition than inflammatory bowel disease (IBD). Functional gastrointestinal disorders are those that arise from no structural or pathological abnormalities that can explain a patient’s symptoms. IBS, which undoubtedly can affect a person’s quality of life and psychological health, is characterized by a hypersensitivity of a patient’s colon to stool, air, and peristalsis, the natural movement of the intestines. Thankfully, the lining of the intestines are completely healthy, and IBS patients have no issues with malnutrition, intestinal inflammation and bloody stools, nor do they harbor an increased risk of malignancy, particularly colorectal cancer.

Conversely, Crohn’s disease and ulcerative colitis, the two main subsets of inflammatory bowel disease (IBD), which affects well over 4 million patients worldwide, is far from a functional gastrointestinal disorder.  It is an autoimmune disease that affects not only the intestines, but can also cause inflammatory arthritis, anemia from blood loss, blood clots in the legs and lungs, malabsorption and weight loss, hepatitis, inflammatory skin and eye conditions, and even a predisposition to certain cancers. Ulcerative colitis results in inflammation anywhere along the colon, beginning in the rectum and traveling upwards towards the small intestine. Depending on the severity and extent of inflammation, and how long patients have been suffering from symptoms of the disease, the risk of colorectal cancer from this constant state of inflammation is a real threat. Crohn’s disease, the other main subset under the umbrella of inflammatory bowel disease, can affect anywhere along the gastrointestinal tract (from mouth to anus), and can result in strictures (narrowing of parts of the intestine), fistulae (abnormal connections between different organs or sections of bowel), and abscesses, (collections of pus) either inside the abdomen, or around the anus. Thankfully, there are new therapies in our armamentarium to fight the inflammation, and we have more efficient, innovative techniques to help us screen for colorectal cancer in our high-risk IBD patients.

Clearly, the difference between IBD and IBS goes way beyond the acronym. This is not to say that irritable bowel syndrome cannot permeate many aspects of patients’ lives: When bouts of abdominal pain and a change in bowel habits do occur, the symptoms can be disruptive. However, and as evidenced by the readers’ commentary of the two columns in the Times, many do think that IBS and IBD are one and the same. Instead, they are in no way comparable — the medications used in IBS are targeted to treat symptoms of the syndrome, while the anti-inflammatory and immune-altering medical therapies that those with IBD require work to dampen the inflammation that leads to the potentially devastating consequences of untreated disease.

As disseminators of health information, as the New York Times and contributors to KevinMD.com often are, we must get the information right, as to not further confuse patients. The paper’s two pieces on IBD were highly informative, and alerted patients to wonderful organizations like the Crohn’s and Colitis Foundation of America (CCFA), which has a wealth of online resources for IBD patients and their caregivers. The CCFA provides an extensive patient and physician network to raise IBD awareness and support for basic and clinical research in IBD. Importantly, the Times columns also helped those that suffer from IBD and its complications to remember that there are many others like them, that they can live fruitful and productive lives, and that they need not be afraid to discuss their gastrointestinal symptoms without the “ick” factor.

Sophie M. Balzora is a gastroenterologist and can be reached on Twitter @SophieBalzoraMD.

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  • Kristy Sokoloski

    Very good piece. One question though. I know that IBS can cause abdominal pain as you stated in the article but can it also cause tenderness to the touch?

    • Sophie Balzora, MD

      Good question – yes, sometimes with IBS, people can experience abdominal tenderness on exam.

      • Kristy Sokoloski

        Dr. Sophie, thank you so much for the answer to this question. It’s very helpful.

  • Duncan Cross

    Thanks for this piece — I’ve had IBD for 20 years, and have sometimes had to explain the difference between IBD and IBS. That said, I feel the CCFA is primarily a pharma marketing group, and not really that interested in the day-to-day experience of living with IBD. I quit my membership several years ago.

    • Sophie Balzora, MD

      Thanks Duncan. Over the past decade or so, there have been many new medications that have been approved for IBD, which has been great for patients refractory to many of the more traditional meds. I find my patients do benefit from CCFA-organized patient support groups and small discussion groups led by IBD-ologists. Perhaps this may be of benefit to you, and certainly to others given your personal experience with the disease. Thanks again for your post.

      • Duncan Cross

        I find self-organized patient groups like Crohnology more helpful than the CCFA. The CCFA events I have attended seemed to be organized more for the benefit of worried parents, not patients.

        Many of those new drugs are some version of TNF-alpha inhibitor, copies of Remicade. I burned out on Remicade and Humira (Abbott’s copy) before getting surgery that put me into remission. The only drug that made a real difference for me before surgery was J695, an experimental Abbot product that they shelved after Remicade started making major profits.

        CCFA’s advocacy for research follows the trends in pharma pretty closely. There is no support for other approaches to the disease — diet, LDN, antibiotics, etc — that might benefit patients but lack the support of major pharmaceutical companies.

        The most effective medical treatment — as reported by hundreds of IBD patients on Crohnology — is medical cannabis (granted, Remicade and prednisone are right behind it). But CCFA would never tell you it’s an option. I don’t use cannabis myself, but the bias on CCFA’s part is telling.

  • Jewel Markess

    I don’t have personal experience, but I had a cat with IBD (yes, cats get it and it’s similar). It’s nasty in cats too, maybe even nastier than in humans.

  • Sophie Balzora, MD

    IBDMom – I couldn’t agree with you more. To characterize IBD as an “uncomfortable” condition does a disservice to our IBD patients. Granted, the severity of illness can differ widely from patient to patient, but it’s a chronic disease that requires lifelong medication, and for many can result in very serious morbidity when the disease is active/not in remission. Hopefully with increased social awareness, people can be more sympathetic to the important issues you’ve raised.

  • Sophie Balzora, MD

    Great question. The “short” answer is that there’s no one test that can definitively diagnose either condition. However, there are some “alarm symptoms” that patients complain of that make us lean away from a diagnosis of IBS, and more towards IBD (or another organic digestive disease). Some examples include blood in the stool, unintentional weight loss, diarrhea that wakens you from sleep, fevers, or unexplained anemia, to name a few. A patient’s story, his family history, and imaging and lab tests, procedures, etc, as warranted, are necessary to make a diagnosis of IBD. Hope this helps.

  • Sara Stein MD

    Great article Sophie! reposted.

  • JW

    I have a lot of “alarm symptoms” of IBD, but my doctor can’t find that (he really tried hard).

    However I just wanted to point out that:

    1) not being able to find pathology which is the same as other diseases, doesn’t mean no pathology exists, it just means it’s not the same as other diseases that we currently know how to test. I believe that many diseases we don’t fully understand yet operate on a cellular level. They don’t cause gross tissue damage (thus you can’t find them easily on imaging tests), but that doesn’t mean they are nonorganic. We are making new advances all the time, although much of it goes to better funded diseases (did you know scientists just recently found an entirely new kind of inflammation in the brains of people with MS, which is not viewable with traditional MRI?).

    2) With a diagnosis of IBS, I have malabsorption, and I am officially underweight. (I have other “red flag” symptoms, too, but as I said, celiac, Crohns, etc. were ruled out.)

    3) This might surprise you, but we do know of some pathology for IBS. My doctor told me that incorrect nerve impulses cause faulty motion of the GI tract, or something like that. I read something about nerve problems in the literature, also, although that was somewhat different. Here’s a recent example paper (I can see only the abstract):

    That being said, I do realize that IBS doesn’t cause the same risk factors for widespread gross inflammatory damage to organs, that IBD does.

    While I was relieved because of that to not have Crohn’s (the most likely suspect), on the other hand I was a little disappointed to not get a diagnosis with a mature treatment protocol. I have other diagnoses (including a connective tissue disease–also with no mature treatment protocol) and my HRQoL is poor. Having some help with digestion would likely improve things, but it is somewhat unlikely that the science will move fast enough to help me.

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