Irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) often get mixed up, and the terms are sometimes used interchangeably. It’s easy to see why: The acronyms are similar, and both are gastrointestinal (GI) disorders that share many of the same symptoms, including diarrhea and abdominal pain.
But IBS and IBD are fundamentally distinct disorders that require different treatment approaches, and one can lead to more serious health complications—including strictures, fistula (which can necessitate surgery) and colorectal cancer. For World IBD Day, here’s an overview of both conditions, why it’s important to know the difference and the innovative treatments Johnson & Johnson is studying.
What is irritable bowel syndrome?
IBS is a group of different conditions that affect the stomach and intestines. People with IBS experience episodes of diarrhea and/or constipation, with or without gas, bloating, mucus in stool and abdominal cramping. As a syndrome, it’s technically a collection of symptoms rather than a disease.
An estimated 10% to 15% of people have IBS, and women are twice as likely to have it. IBS symptoms can be chronic or episodic, meaning they occur routinely or come and go over time. It’s the most commonly diagnosed GI condition, and despite a lack of detectable inflammation, it can compromise quality of life significantly.
Doctors aren’t sure what causes IBS. Some experts believe it can be triggered by an intolerance or sensitivity to one or more foods. Other potential explanations include an overgrowth of bacteria in the small intestine, according to the National Institutes of Health.
To diagnose IBS, doctors typically run tests that rule out other diseases; there’s no specific diagnostic tool for the condition. Symptoms are often treated with over-the-counter or prescription medication—for example, an antibiotic if a bacterial infection is the cause. IBS might also be managed with lifestyle changes, such as avoiding triggering foods and eating more fiber.
What is inflammatory bowel disease?
IBD is an umbrella term for two similar yet distinct immune-mediated conditions: ulcerative colitis (UC) and Crohn’s disease, says Marion Vetter, M.D., M.S., Vice President, Head of GI Clinical Development at Johnson & Johnson Innovative Medicine. The most common symptoms of both are persistent diarrhea, abdominal pain, bloody stools, weight loss and fatigue. IBD also often affects joints or the skin, highlighting a systemic inflammatory component.
Unlike IBS, IBD causes inflammation of the mucus membrane that coats the GI tract. “Patients with IBS do have GI-related symptoms, which can be similar to IBD symptoms, but there’s no clear inflammatory component,” explains Dr. Vetter.
To diagnose IBD, doctors look for inflammation. They use blood and stool tests and rely on endoscopy of the lower and upper GI tract, which includes taking intestinal tissue samples that are assessed by a pathologist. Imaging tools such as MRI and ultrasound provide an essential additional diagnostic pillar to view the lining and integrity of the GI tract.
About 3 million Americans live with IBD, according to the Centers for Disease Control and Prevention, and it affects men and women at about the same rates. Exactly what causes IBD isn’t known; experts believe it may be the result of the way a person’s immune system responds to microbials, which are abundant in the intestinal lumen. Genetic research has helped the scientific community understand the disease much better. Genetic susceptibility does play a role in the disease process, and the interplay of genetic and environmental factors is a focus of continuous research, says Dr. Vetter.
What makes IBD a more worrisome diagnosis than IBS is that it can lead to more serious complications. The inflammation caused by IBD can damage the intestinal tract and often requires surgery to treat. Due to continuous chronic inflammation, people with IBD also have an increased risk of developing colorectal cancer.
Treating IBD to improve patient lives
While there’s not yet an ultimate cure for IBD, Johnson & Johnson has long focused on developing treatments and improving the health and quality of life of people with the condition worldwide.
Johnson & Johnson is working with the U.S. Food and Drug Administration to evaluate clinical data in adult patients with moderately to severely active UC focusing on the interleukin 23 pathway, a cytokine that is known to be a driver of immune-mediated diseases, including IBD.
Dr. Vetter says the company has submitted an application in Europe for approval to use the therapeutic to treat Crohn’s disease.
Johnson & Johnson also launched a study to evaluate the safety and efficacy of a targeted oral peptide inhibitor designed to block IL-23 for patients with UC. Clinical trials have shown the medication improves symptoms of psoriasis, and results from those studies were published in February in the New England Journal of Medicine and presented at the American Academy of Dermatology meeting in March.
