Study shows UK South Asians with inflammatory bowel disease respond the same to commonly used treatments as White patients, but may have slightly increased risk of side effects to certain medications
A new study published today by researchers at Imperial College Healthcare NHS Trust and Imperial College London has discovered that UK inflammatory bowel disease (IBD) patients of White and South Asian ethnicity respond the same to commonly used treatments, despite the disease itself being different in each group.
Funded by Bowel Research UK and supported by the Imperial and Cambridge NIHR Biomedical Research Centres (BRCs), this study means patients can be reassured that current treatments work equally well for both ethnic groups.
The study also revealed South Asian IBD patients were at a slightly increased risk of experiencing side effects from certain treatments, highlighting the need for clinicians to be vigilant while monitoring this group of patients.
The findings were published today in eClinicalMedicine.
Around 300,000 people in the UK live with IBD, which includes Crohn’s disease and ulcerative colitis – chronic conditions that cause inflammation of the digestive tract and often require long-term treatment or surgery to manage symptoms.
Study highlights the need for inclusive research
The study analysed data from more than 26,500 people in the UK’s IBD BioResource and is the largest analysis of ethnicity and treatment outcomes in IBD ever conducted in the UK.
The study provides valuable insights into treatment outcomes and side-effect risks in an underrepresented population. Most clinical trials and studies of IBD treatments carried out so far have been carried out in predominantly White patient populations.
This latest study builds on earlier research from the same Imperial-led team, which revealed that IBD presents differently among ethnic groups, but that there is equal access to treatment in the UK.
The new study published today shows the need for inclusive research to highlight how diseases may affect people of different backgrounds differently and ensure that treatments are safe and effective for everyone living with IBD.
Dr Sharmili Balarajah, gastroenterology specialty registrar at Imperial College Healthcare NHS Trust, clinical research fellow at Imperial College London, and lead author on the study said: “Earlier this year we found that inflammatory bowel disease (IBD) is different in people of different ethnicities but that in the NHS, everyone receives equal access to treatment.”
She continued: “Our new paper shows that despite these differences, South Asian and White IBD patients respond the same to treatment, although South Asian patients may be slightly more likely to experience side effects from some of the treatments we use. These results are reassuring as they show the treatments work in both groups – so patients hearing this news don’t need to be worried. It just means that their clinicians need to be vigilant while monitoring South Asian patients.”
Kathryn Pretzel-Shiels, Chief Executive of Bowel Research UK said: “IBD can be a lifelong and often debilitating disease, usually diagnosed when people are still in their twenties or thirties. By funding this important work, Bowel Research UK is helping to ensure that treatments are equally safe and effective for everyone, regardless of ethnicity. This research shows how inclusive science can directly improve care and quality of life for patients.”
Consultant gastroenterologist Professor Horace Williams, who leads the research group within Imperial College Healthcare NHS Trust and Imperial College London said: “We have been studying ethnicity and its impact on IBD at Imperial for many years. Until now, our understanding of treatment response in patients of non-white ethnicity has been limited. These findings demonstrate why we need people from all backgrounds that reflect our patient population to take part in research. This is essential for us to tailor and deliver the best care for patients.”
Research at Imperial College Healthcare NHS Trust is supported by the NIHR Imperial Biomedical Research Centre (BRC), a translational research partnership between Imperial College Healthcare NHS Trust and Imperial College London, which was awarded £95m in 2022 to continue delivering world class research.
Dr Sharmili Balarajah
Notes to Editors
For media enquiries: press@bowelresearchuk.org
About the study
A large-scale comparison of clinical outcomes to IBD therapies in White and South Asian ethnicities was led by Imperial College London in collaboration with the University of Cambridge, using data from the UK IBD BioResource. The study was published in eClinicalMedicine on Tuesday 18 November 2025. Funding was provided by Bowel Research UK and the study was supported by the National Institute for Health and Care Research (NIHR) Biomedical Research Centres (BRCs) at Imperial and Cambridge, using data from the NIHR IBD Bioresource (IBD BioResource).
About Bowel Research UK
Bowel Research UK funds life-changing research into bowel cancer and bowel disease. Over 16,000 people die from bowel cancer every year in the UK and more than a million live with bowel conditions. By investing in cutting-edge science and supporting the next generation of researchers, Bowel Research UK is saving and improving lives.
www.bowelresearchuk.org
About Imperial College Healthcare NHS Trust
Imperial College Healthcare is one of the largest NHS Trusts in England, with over 15,000 staff providing acute and specialist healthcare to over one million people a year. The Trust runs five hospitals in central and west London – Charing Cross, Hammersmith, Queen Charlotte’s and Chelsea, St Mary’s and the Western Eye. Find out more: www.imperial.nhs.uk
About Imperial College London
We are Imperial – a world-leading university for science, technology, engineering, medicine and business, where scientific imagination leads to world-changing impact. As a global top-ten university based in London, Imperial brings together students, staff and partners to tackle some of the world’s toughest challenges in global health, climate change, AI and more.
www.imperial.ac.uk