In gastroenterology, monitoring polyps is fundamental in order to detect a cancer. It may be difficult for surgeons to decide whether he should remove a polyp or not. A wrong decision may generate unjustified costs or be dangerous for the patient health. To help their diagnosis, physicians may need images of previously treated cases. For this purpose, we present in this paper a semantic image retrieval approach focused on endoscopic gastroenterological images. This approach is based on a slight extension of classical description logic reasonings, associated with a polyp ontology and a suited image annotation mechanism.