I am an internationally renowned researcher, and am interested in the natural history, diagnosis, and treatment of functional gastrointestinal disorders, such as irritable bowel syndrome and functional dyspepsia. I study the epidemiology of these disorders, as well as how best to treat them using randomised controlled trials design, as well as evidence synthesis techniques, such as systematic review and meta-analysis. I am a leading proponent of evidence-based medicine in UK Gastroenterology. I collaborate widely with other researchers worldwide, with 380 published articles. My original and review articles have been cited over 16,000 times, to date, and my h-index is 70 on Scopus and 65 on Web of Science. In 2020, I was listed as a highly cited researcher for 2020 by Clarivate/Web of Science, an accolade that identifies academics who produced multiple papers ranking in the top 1% by citations for their chosen field and year of publication, demonstrating significant influence among their peers. This is a list of the top 0.1% of the global research community. I am principal investigator (PI) or deputy PI on three NIHR-funded trials, TRITON, ATLANTIS, and MODULATE. I have been awarded >£6 million of grant income as PI, deputy PI, or co-investigator. I am an Associate Editor for Alimentary Pharmacology and Therapeutics, handling papers dealing with the functional gastrointestinal disorders, and have served on NICE guidelines groups.