The invention relates to a device (12) for treating a body tissue presenting a prolapse. The device comprises: at least two arms (14, 16), each arm having a distal end (40) for gripping the tissue, a proximal maneuvering end (42) opposite the distal gripping end, and an elongate portion (44) comprised between the distal gripping end and the proximal maneuvering end, each elongate portion extending along a main direction (X). Furthermore, each arm is rotatable between an angular catching position (a1, a2) and an angular clamping position (e1, e2) around a rotation axis (A1, A2) substantially parallel to the main direction, and the device comprises a guide member (25) able to limit the transverse movement of the arms relative to one another along a direction perpendicular to the main direction.