Professor Bridgewater is a medical oncologist specializing in gastrointestinal cancer. He has led and contributed to landmark studies in gastrointestinal malignancy, focusing on clinical and scientific research in gastrointestinal cancer. His work includes chemotherapy, biliary cancer, bowel cancer, cancer of unknown primary, gastro-intestinal cancers, and liver cancer. He has been involved in personalized oncology treatment, targeting faulty genes in cancers with novel therapies. His roles include leading the National Cancer Research Institute (NCRI) Study Group for upper gastrointestinal malignancy and the Genomics England Upper Gastrointestinal Workstream.