Racial Disparities in Inflammatory Bowel Disease: Closing the Gaps in Diagnosis, Treatment and Clinical Trials

The incidence of inflammatory bowel disease is increasing in populations around the world, yet significant racial disparities remain in diagnosis, treatment and clinical trial participation, according to a study co-authored by Houston Methodist Hospital gastroenterologist Dr. Bincy Abraham, a leading expert on IBD.

Traditionally thought to affect primarily people of Northern European descent, with the highest risk seen in the Ashkenazi Jewish population, IBD has increased significantly in people in Asia, Africa and South America in recent decades.

In the study, published in Inflammatory Bowel Diseases, Dr. Abraham and a panel of other IBD experts reported that about 85%-90% of participants in IBD clinical trials are white, leaving Black, Hispanic and Asian participants substantially underrepresented.

Recent studies estimate that for every 100 white patients with IBD there are 60-75 non-white patients with IBD. In the 1970s-1980s, estimates put the IBD ratio at 30-35 non-white patients for every 100 white patients.

Authors of the new study identified four priority areas to improve health equity of underserved minorities with IBD: better access to care, more accurate assessment of treatment outcomes, greater incorporation of Black and Hispanic patients in therapeutic clinical trials and an investigation into the environmental factors that lead to the increase in disease incidence.

Delayed diagnosis and treatment gaps

Dr. Abraham said the imbalanced makeup of clinical trials raises questions about the effectiveness of treatments across different racial groups.

"A drug may work well for white patients, but we lack sufficient data to know if the same holds true for Black, Hispanic or Asian patients," said Dr. Abraham.

Some therapies, particularly newer biologics, can be affected by a patient's personal genetic and ethnic makeup, and clinicians may need to alter dosing or frequency of dosing to achieve the desired effect.

"When only 1%-2% of patients in the clinical trial are Black, or Asian, or Hispanic, we don't have that necessary information, and we have to figure it out with trial and error with every new drug that becomes available," Dr. Abraham explained.

Dr. Abraham noted that one potential reason for racial disparity in clinical trials is a lingering legacy of historical mistreatment and marginalization of care.

To this day, many Black patients report feeling unheard when seeking care, and they are often misdiagnosed with stress-related conditions or irritable bowel syndrome (IBS) instead of undergoing early testing for IBD.

Due to the long ingrained belief that IBD doesn't often affect people of color, some primary care physicians and gastroenterologists may not initially consider IBD, leading to a prolonged journey before receiving appropriate care.

"Some patients go months or even years before getting a colonoscopy, the gold standard for inflammatory bowel disease diagnosis," Dr. Abraham said. "This diagnostic delay can result in worse outcomes, including more severe disease by the time of diagnosis and a higher likelihood of needing surgery."

Indeed, studies show that Black patients with IBD are more likely to require surgery and experience higher postoperative complication rates compared to white patients.

The role of environmental and dietary factors

While genetics play a role in IBD, environmental factors have increasingly come under scrutiny. Dr. Abraham pointed to rising cases in countries where IBD was once rare, such as Japan and India. Recent research suggests that changes in diet — particularly increased consumption of processed foods — may contribute to the rising incidence.

"Westernization of the diet and lifestyle appears to be a driving factor," said Dr. Abraham, adding that even rural communities now have access to highly processed foods, potentially affecting gut microbiota and immune responses.

Addressing these disparities requires a multipronged approach, according to Dr. Abraham.

• Increase awareness among primary care physicians about the prevalence of IBD across all racial groups: Physicians should consider early testing for non-white patients presenting with chronic gastrointestinal symptoms rather than attributing them to stress or diet.
• Improve clinical trial diversity: A greater effort is needed to recruit and retain diverse participants, something that Dr. Abraham emphasized not only advances scientific knowledge and ensures new treatments are effective for all populations, but also provides patients with access to cutting-edge treatments, often at no cost.
• Prioritize patient education and trust-building initiatives: Ensuring that patients of all backgrounds feel heard and understood can help bridge the trust gap and encourage earlier medical intervention.

"We need to be cognizant of the changing epidemiology of IBD, listen to our patients, and ensure they receive timely and appropriate care," Dr. Abraham said. "Better representation in clinical trials and improved diagnostic practices will lead to better outcomes for all patients, regardless of race or ethnicity."