A cassette intended to be inserted into an irrigation or aspiration machine used in endoscopy comprising an irrigation tube (1i) or an aspiration tube (1a) and a support (5) furnished with one (3i) or with two inlet plugs (3i, 3a) and with one (7i) or with two outlet plugs (7i, 7a), the tube or the two tubes forming an elbow (9i, 9a) for engaging with the inlet and outlet plug or the two inlet and outlet plugs in a respectively incoming (E) and outgoing (S) direction of flow and forming a segment of irrigation (11i) or of aspiration (11a) pumping in the incoming direction (E) of flow, characterized in that the support (5) comprises a T guide (13) shaped to the head of the T so as to protect the elbow (9i, 9a) of each tube (1i, 1a) and shaped along the body of the T as a slot (19) guiding the tube or the two tubes in the outgoing direction of flow (S), the T guide (13) running between the inlet plug or the two inlet plugs (3i, 3a) so as to form the segment of irrigation (11i) or of aspiration (11a) pumping on either side of the slot (19) between each inlet plug (3i, 3a) and the head of the T.