Endoscopic treatment system

An endoscopic treatment system is designed to suture or resect a lesion while ensuring the ease of insertion into a deep region in the large intestine. The endoscopic treatment system comprises an endoscope and a therapeutic instruments insertion aid into which the endoscope is inserted. The endoscopic treatment system further comprises: a pair of clamp forceps that clamps and lifts a living-body tissue; a lateral hole formed in the therapeutic instruments insertion aid and used to control the position of the living-body tissue clamped and lifted by the pair of clamp forceps or to control the lifting thereof; a ligature used to ligate the living-body tissue whose position or lifting is controlled by the lateral hole; and a cutter used to resect the living-body tissue at a position between a region ligated with the ligature and a region clamped and lifted with the pair of clamp forceps.