Professor Siwan Thomas-Gibson is a leading expert in the field of gastrointestinal medicine, specializing in high-quality colonoscopy procedures and early colorectal neoplasia management. Accredited as a bowel cancer screening colonoscopist since 2007, she prioritizes patient care. Her expertise encompasses various gastrointestinal conditions, including inflammatory bowel disease, irritable bowel syndrome, indigestion, and post-cancer treatment bowel symptoms, employing evidence-based approaches to diagnosis and treatment. Recognized with the prestigious British Society of Gastroenterology Hopkins prize in 2018, Professor Thomas-Gibson has spearheaded initiatives to enhance safety and standards in endoscopy. An esteemed educator, she frequently contributes to national and international platforms. Appointed as a Chair at Imperial College London in 2020, she continues to make significant contributions to gastroenterological care, research, and education.