Professor Ris is an expert in minimally invasive colorectal surgery (IBD, oncology and MHS rectal surgery) and pelvic floor disorders. He is also responsible for the management of abdominal peritoneal carcinoma (intra-abdominal hyperthermic chemotherapy and PIPAC) and works regularly with the team of gynecology on ovarian carcinoma. He is one of the founding members of the Swiss group for the management of this disease (Swiss peritoneal cancer group).