Coeliac disease and Irritable Bowel Syndrome (IBS) present one of the most challenging diagnostic dilemmas in modern gastroenterology. With overlapping symptoms and varying presentations, these two distinct conditions often lead to confusion amongst both patients and healthcare providers, potentially resulting in delayed diagnoses and inappropriate treatment approaches. This article explores the intricate relationship between these conditions and examines why coeliac disease is frequently misdiagnosed as IBS.
Understanding the Fundamental Differences
Coeliac disease is an autoimmune condition where the ingestion of gluten triggers an immune response that damages the small intestinal mucosa (1). According to the NHS, this damage leads to malabsorption of nutrients and various gastrointestinal and systemic symptoms (1). In contrast, IBS is a functional gastrointestinal disorder characterised by recurrent abdominal pain and altered bowel habits, with no apparent structural abnormalities (2).
The commonality between these conditions lies in their shared symptom profile. Both conditions typically manifest through abdominal pain and discomfort, accompanied by bloating and excessive wind (1,2). Patients often experience altered bowel habits, which may alternate between diarrhoea and constipation. Furthermore, both conditions frequently result in fatigue, general malaise, and occasional nausea and vomiting, making initial distinction particularly challenging.
The Diagnostic Challenge
The similarity in symptom presentation often leads to diagnostic confusion. The substantial overlap in symptoms between these conditions presents the primary challenge in differential diagnosis. Both conditions can cause significant gastrointestinal distress, and the symptoms may wax and wane over time. This variability can make it particularly difficult to distinguish between the two conditions without proper diagnostic testing.
Coeliac disease does not always present with classical symptoms. Some patients may experience minimal gastrointestinal symptoms but suffer from extra-intestinal manifestations (3). These can include unexplained anaemia, osteoporosis, and various neurological symptoms (3). Some patients develop skin conditions, particularly dermatitis herpetiformis (4), while others may experience reproductive problems. These atypical presentations may not immediately suggest coeliac disease to healthcare providers, leading to a potential IBS misdiagnosis.
Historically, IBS has been diagnosed using symptom-based criteria, such as the Rome criteria, without necessarily excluding other conditions first (2). This approach, while practical in many cases, may lead to missed diagnoses of coeliac disease and other organic conditions.
The Impact of Misdiagnosis
The consequences of misdiagnosing coeliac disease as IBS can be significant and far-reaching. From a health perspective, untreated coeliac disease can result in serious complications. Patients may develop significant nutritional deficiencies and face an increased risk of certain cancers (3). The ongoing intestinal damage can lead to osteoporosis and fertility problems, while some patients develop neurological complications or additional autoimmune conditions.
The impact on quality of life is equally significant. Patients with undiagnosed coeliac disease who continue to consume gluten experience perpetual intestinal damage and systemic inflammation. This ongoing damage typically manifests as chronic fatigue and reduced energy levels (5). Many patients develop mood disorders and anxiety, while their work productivity often suffers. The combination of these factors frequently leads to social isolation and compromised overall wellbeing.
Improving Diagnostic Accuracy
To address this diagnostic challenge, healthcare providers should implement systematic screening for coeliac disease in patients presenting with IBS-like symptoms. According to the National Institute of Diabetes and Digestive and Kidney diseases, this process should include serological testing for tissue transglutaminase antibodies (tTG-IgA) and total IgA levels to ensure accurate interpretation of results (6). In selected cases, genetic testing for HLA-DQ2 and HLA-DQ8 may be warranted (6).
Risk factor assessment plays a crucial role in the diagnostic process. Clinicians should carefully consider factors that increase the likelihood of coeliac disease, including family history, personal history of other autoimmune conditions, and associated conditions such as Type 1 diabetes or thyroid disease. Geographic and ethnic background may also influence risk assessment.
A comprehensive clinical evaluation remains essential. This should encompass a detailed medical history, physical examination, and thorough review of extra-intestinal symptoms (6). Clinicians should assess nutritional status and carefully evaluate dietary patterns and their correlation with symptoms.
The Role of Diet in Diagnosis
The relationship between diet and symptoms can further complicate the diagnostic process. Many patients with IBS report improvement with a gluten-free diet, leading to potential confusion with coeliac disease. This phenomenon, known as non-coeliac gluten sensitivity (NCGS), represents a distinct entity that requires careful differentiation from both IBS and coeliac disease (7).
Future Directions and Recommendations
Healthcare providers should maintain a high index of suspicion for coeliac disease in patients presenting with IBS-like symptoms. Serological testing should be performed before confirming an IBS diagnosis, and providers should consider the broader spectrum of coeliac disease presentations. Regular follow-up and reassessment of diagnosis become crucial if symptoms persist or change.
For patients, the journey toward accurate diagnosis requires active participation. This includes maintaining detailed symptom diaries and avoiding self-diagnosis or implementing restrictive diets without medical supervision. Patients should seek medical evaluation if symptoms persist or worsen, and should not hesitate to request coeliac testing, especially when risk factors or family history are present.
Conclusion
The similarity between coeliac disease and IBS symptoms presents a significant diagnostic challenge in clinical practice. Understanding the distinct nature of these conditions, implementing appropriate diagnostic strategies, and maintaining awareness of the potential for misdiagnosis are crucial steps in ensuring accurate diagnosis and appropriate treatment.
The consequences of misdiagnosing coeliac disease as IBS can be substantial, affecting both immediate health outcomes and long-term wellbeing (3). Healthcare providers must remain vigilant and consider coeliac disease in their differential diagnosis of IBS-like symptoms, particularly in high-risk populations.
Moving forward, improved diagnostic algorithms, better understanding of the conditions' pathophysiology, and enhanced awareness among healthcare providers and patients will be essential in reducing diagnostic delays and improving outcomes for individuals affected by these conditions.
References
- NHS. (2024). Coeliac disease: Overview.
- NHS. (2024). What is IBS? Irritable Bowel Syndrome.
- Therrien, A., Kelly, C. P., & Silvester, J. A. (2020). Celiac Disease: Extraintestinal Manifestations and Associated Conditions. Journal of clinical gastroenterology, 54(1), 8–21.
- Therrien, A., Silvester, J. A., Leffler, D. A., & Kelly, C. P. (2020). Efficacy of Enteric-Release Oral Budesonide in Treatment of Acute Reactions to Gluten in Patients With Celiac Disease. Clinical gastroenterology and hepatology, 18(1), 254–256.
- Jelsness-Jørgensen, L. P., Bernklev, T., & Lundin, K. E. A. (2018). Fatigue as an Extra-Intestinal Manifestation of Celiac Disease: A Systematic Review. Nutrients, 10(11), 1652.
- National Institute of Diabetes and Digestive and Kidney diseases. (2024). Celiac Disease Tests.
- Biesiekierski, J. R., & Iven, J. (2015). Non-coeliac gluten sensitivity: piecing the puzzle together. United European gastroenterology journal, 3(2), 160–165.