Delayed diagnosis of inflammatory bowel disease linked to worse clinical outcomes

Patients who wait longest to be diagnosed with inflammatory bowel disease (IBD) double their risk of adverse clinical outcomes such as scarring of the bowel, gut complications, and bowel surgery. We conducted the largest systematic review of global literature of clinical outcomes of inflammatory bowel disease to date. The study, led by researchers from St George’s University of London, Imperial College London, and University College London (POP-IBD research group), reviewed 101 studies representing over 100,000 people with Crohn’s disease and ulcerative colitis. 

Study Key Findings: Delays in Diagnosis Worsen Clinical Outcomes

The review reveals that delayed diagnosis of IBD correlates with a more severe disease trajectory and increased healthcare interventions. Notably, diagnostic delays are linked to higher rates of complications in both Crohn's disease and ulcerative colitis:

Crohn’s Disease (CD): Patients who experienced delays in diagnosis were more likely to develop severe disease complications. Delayed diagnosis was associated with an 88% higher likelihood of developing stricturing disease (characterised by bowel narrowing) and a 64% increase in the risk of penetrating disease, where inflammation can lead to fistulas or abscesses. Additionally, the odds of requiring intestinal surgery were over twice as high (OR: 2.24) for those diagnosed later.

Ulcerative Colitis (UC): For UC, delays in diagnosis significantly increased the likelihood of colectomy (OR: 4.13), a surgical procedure where part or all of the colon is removed. This finding underscores the urgency for timely diagnosis to help avoid surgical interventions where possible.

The Diagnostic Timeline: Variability Across Regions

Diagnostic timelines varied significantly, especially between high-income and low- and middle-income countries. The median diagnostic interval for Crohn's disease was 7 months, while ulcerative colitis averaged a 4.6-month delay. However, in lower-income regions, these delays often extended, with patients waiting an average of 11.7 months for Crohn’s diagnosis and 7.8 months for UC.

Factors contributing to diagnostic delays include the overlapping symptoms of IBD with other conditions, such as irritable bowel syndrome (IBS) or haemorrhoids, which can make diagnosis challenging. In low- and middle-income countries, limited access to specialist resources and the prevalence of infections with similar symptoms, such as intestinal tuberculosis, often complicate accurate and timely diagnosis.

Path to Diagnosis: Patient-Related and Healthcare-Related Delays

The study categorises diagnostic delays into two main intervals:

Patient-Related Delays: This interval covers the time from symptom onset until the patient seeks medical attention. In the case of ulcerative colitis, patient-related delays were often more significant, potentially due to symptom intermittency and mild early signs that might be overlooked.

Healthcare-Related Delays: This interval includes the time from the initial clinical consultation until a confirmed diagnosis of IBD is established. For Crohn’s disease, healthcare-related delays tended to be more prominent, likely influenced by the broad symptom range and challenges in differentiating Crohn’s from other gastrointestinal conditions without extensive testing.