Safety issues/concerns with device use reported by the manufacturer and requested product recall and to stop use of product.

Is ORISE Gel an effective and feasible submucosal injecting solution during endoscopic resection of large colorectal polyps.

Endoscopic resection of large colonic polyps is preferred over Surgical resections due to lower morbidity and preservation of the colon and its functions.

The use of submucosal injection is essential for a successful resection (EMR/ ESD). Injection of fluid into the submucosa cushions and isolates the tissue just before capture of the target lesion with a snare, thereby reducing thermal injury and the risk of perforation during EMR. ESD requires a long period of submucosal dissection and that involves multiple injections to maintain the submucosal cushion; without which the risk of perforation increases.

A mixture of normal saline solution + epinephrine and blue dye like indigo carmine is the commonly used injecting solution. However, Saline dissipates very quickly leading to frequent and multiple injections. This leads to longer procedure time.

Studies have demonstrated long-lasting effects of colloids when injected in the submucosal space. ORISE gel is a newly licensed injecting solution which contains a poloxamer agent leading to longer lasting submucosal cushion effect.

Multicentre prospective observational cohort study

Primary Objective : Primary Objective To evaluate the technical feasibility, effectiveness & safety of the ORISE gel as an injecting solution on its own during endoscopic resection of colorectal polyps (ability to start and finish the resection with ORISE).

Secondary Objective : To identify Polyp Resection Time (PRT) and the amount of ORISE gel used during resection of large colorectal polyps.

Inclusion Criteria:

• > 18 years old at the date of consent
• Subjects referred for EMR for the excision of:

Treatment naïve, laterally spreading sessile, flat polyps or adenomas of the colon equal to or greater than 20 mm in largest dimension, assessed by the investigator to be suitable for EMR or ESD.

Exclusion Criteria:

• Lesions less than 20 mm in largest dimension
• Subjects with ulcerated depressed lesions (Paris type III-excavated) or biopsy proven invasive carcinoma
• Scarred polyps
• Endoscopic appearance of deep invasive malignancy
• Previous partial resection or attempted resection

All patients undergoing EMR or ESD at each recruiting centre who meet below eligibility criteria will be invited to participate.

Non identifiable Data regards primary and secondary outcome measures to be shared with other investigators