When symptoms like abdominal pain, bloating, and unpredictable bowel habits become part of daily life, it’s natural to start looking for answers. For many, the first thought is irritable bowel syndrome (IBS), a condition that’s often used as a catch-all diagnosis for gut issues that don’t show up on standard tests. However, there are other, potentially more treatable, causes of ongoing digestive symptoms.
Inflammatory bowel disease (IBD), which includes Crohn’s disease and ulcerative colitis, is one of the key conditions that needs to be ruled out. However, it’s not the only one. Coeliac disease, small intestinal bacterial overgrowth (SIBO), bile acid malabsorption, and even pelvic floor dysfunction can all mimic IBD to varying degrees.
Understanding the differences is crucial, not only for managing symptoms, but for getting the right treatment.
IBD vs IBS: Two different conditions
The conditions IBD and IBS are often confused, and while their acronyms are similar, the conditions themselves are quite distinct.
IBD is a group of autoimmune disorders characterised by chronic inflammation in the gastrointestinal tract. That inflammation can cause visible damage to the bowel, which is detectable on scans, endoscopies, and biopsies. Common symptoms include abdominal pain, bloody diarrhoea, weight loss, fatigue, and in some cases, fever or joint pain. It’s a long-term condition that often requires medication to control inflammation and reduce flare-ups.
IBS, on the other hand, is a functional disorder. That means the gut looks normal under the microscope but doesn’t function as it should. Symptoms can include cramping, bloating, diarrhoea, or constipation (or both), but there is no underlying inflammation or structural damage. While IBS can be deeply uncomfortable and impact quality of life, it’s not associated with the same long-term complications as IBD.
This distinction is important because treatments for the two conditions are quite different. Anti-inflammatory medications, immunosuppressants, or biologic therapies are common in IBD, whereas IBS is more often managed with dietary changes, gut-directed therapies, and symptom-based medications.
Could it be coeliac disease instead?
Another condition that’s frequently mislabelled as IBS is coeliac disease, an autoimmune response to gluten that damages the lining of the small intestine. Like IBD, coeliac disease can cause diarrhoea, abdominal discomfort, fatigue, and weight loss. However, unlike IBD, the trigger is dietary, and once identified, it’s entirely avoidable.
Interestingly, there’s also growing evidence of overlap between coeliac disease and IBD. A 2022 study published in The American Journal of Gastroenterology found that people with coeliac disease were at significantly higher risk of also developing IBD. This relationship means that if you’ve been diagnosed with one, it’s worth being aware of the signs and symptoms of the other.
Testing for coeliac disease is relatively straightforward and involves a blood test followed by an endoscopy if results suggest further investigation is needed.
Other common IBD mimics
It’s not just IBS and coeliac disease that can resemble IBD. A handful of other conditions can present with similar symptoms, yet require very different treatment approaches:
Bile acid malabsorption: This occurs when the body doesn’t properly reabsorb bile acids in the small intestine, leading to chronic diarrhoea. It’s frequently mistaken for IBS-D (IBS with diarrhoea), but it responds well to specific medications that bind bile acids.
Small intestinal bacterial overgrowth (SIBO): Happens when excess bacteria grow in the small intestine, fermenting food and causing bloating, gas, and loose stools. Breath testing can help diagnose SIBO, and targeted antibiotics are usually effective.
Pelvic floor dysfunction: This affects how the muscles involved in bowel movements coordinate. It can cause constipation, incomplete emptying, and even abdominal pressure or bloating, again, often mislabelled as IBS or IBD. Physiotherapy can make a significant difference.
Getting the right diagnosis
At the Warwick Bowel and Hernia Clinic, we see many patients who’ve lived for years with a label of IBS, only to discover they’ve been dealing with something else entirely. While IBS is certainly common, it’s not a diagnosis that should be given without ruling out other potential causes. If symptoms persist, worsen, or change over time, it’s worth taking another look.
With the right investigations and a tailored approach, it’s possible to get answers and find a management plan that truly fits. Get in touch with the Warwick Bowel and Hernia Clinic on 01926 492969.
