In 20 to 35% of colonoscopies due to symptoms or for prevention polyps, so-called adenoma, are found. Currently, colonoscopy is the best way to detect bowel tumors and polyps, since these can be biopsied and removed in one working process. If the size of adenoma is larger than 2 cm, resections are usually done in a hospital setting. Foremost for flat adenoma, the resection by snares piece by piece, the so-called piecemeal polypectomy, or piecemeal endoscopic mucosal resection (EMR), is state of the art. Resection will usually follow a submucosal saline injection (saline assisted polypectomy). Recurrences occur in 10 up to 25 %, requiring a reapplication of endoscopic therapy and follow up examinations.