Endoscopic tattoo: the importance and need for standardised guidelines and protocol.

Preoperative endoscopic tattoo is becoming more important with the advent of minimally invasive surgery. Current practices are variable and are operator-dependent. There are no evidence-based guidelines to aid endoscopists in clinical practice. Furthermore, there are still a number of issues with endoscopic tattoo including poor intraoperative visualisation, complications from tattooing and inaccurate documentation leading to the need for intraoperative endoscopy, prolonged operative time and reoperation due to lack of oncologic resection. This review aims to collate and summarise evidence for the best practice of endoscopic tattoo for colorectal lesions in order to provide guidance for endoscopists.