Professor Omar Faiz is the Clinical Director and a Consultant Colorectal Surgeon at St Mark's Hospital and Professor of Practice in Colorectal Surgery at Imperial College. His areas of clinical interest within colorectal surgery are the surgical management of Inflammatory Bowel Disease (IBD), hereditary cancer syndromes, colorectal cancer, and proctology.

He trained in general and colorectal surgery within London and the South East of England and undertook specialist colorectal fellowships at St Mark's Hospital and Valencia University Hospital. He took up a consultant post at Imperial College in 2008 (St Mary's Campus) and then at St Mark's Hospital in 2012.

Professor Faiz has wide research interests and has supervised 20 PhD and MD research fellows at Imperial College. His principal research interests include colorectal surgical epidemiology, health services research, and surgical outcome research. He has authored 250 papers in peer-reviewed journals, 11 book chapters, and three textbooks.

He holds various leadership positions at a national level, including ex-Chairman of the Association of Coloproctology of Great Britain and Ireland (ACPGBI) IBD subcommittee and Chair of the national Ileal Pouch Registry. He has contributed to guideline development for the 'IBD Standards' and NICE in 2015. He also chaired an international gastrointestinal surgery initiative of Global Comparators from 2014 to 2018.

Currently, he represents the ACPGBI on the Inflammatory Bowel Disease Standards board and is the Lead for IBD Surgery for the ACPGBI. He is on the Board of Surgical-European Crohn's and Colitis Organisation (S-ECCO) and is an Associate Editor for the journal Colorectal Disease.

In 2018, the Daily Mail published a Good Doctors Guide for IBD, where Professor Faiz was listed and described as 'a very good, high volume surgeon at a major centre, supported by an excellent team.' His expertise includes laparoscopic surgery, colorectal surgery, anal fissure repair, abdominal wall reconstruction, closure of stoma, colonoscopy, and treatment of conditions such as diverticular disease, fissure, fistula, haemorrhoid, hernia, IBD, proctology, rectal cancer, and small bowel resection.