With reference to the accompanying drawings, the present design includes a bottom edge having straight front and side edges, and a rearwardly convex rear edge. A surface extends upward from the bottom edge, then becomes outwardly convex and extends upward and inward to a lower edge. Above this lower edge lies a front base portion and a rear base portion.The front base portion maintains a generally square cross-section and has an outwardly convex surface which extends upward and inward, and then extends upward to intersect with an outwardly concave surface which extends upward and inward, and then becoming planer and intersecting with the bottom surface of a reservoir portion.The rear base portion intersects with the rear of the front base portion and has side surfaces which extend upward and slightly inward, and from the front is outwardly concave and extends rearward and outward, then becoming outwardly convex, intersects with the rear surface of the rear base portion. The rear surface of the rear base portion has a rearwardly convex surface which extends upward and forward, and then becomes planer and intersects with the bottom surface of the reservoir portion. A rearwardly concave surface is disposed in the central portion of the rear surface of the rear base portion.The reservoir portion includes a planer horizontal top surface defined by inner and outer edges, each having a forwardly convex forward edge and straight side and rearward edges. An upwardly convex surface extends along the rearward edge and rear third of the side edges. From the inner edge a surface extends downward from the rearward edge, and an upwardly concave surface extends downward and inward from the forward and side edges, to a circular recess. From the forward and side edges of the outer edge an outwardly concave surface extends downward and outward, then becomes outwardly convex and extends downward and outward, then downward and inward, becoming outwardly convex again and extending downward and inward to an edge. From this edge a downwardly convex surface extends downward and inward to intersect with the base portions. From the rear edge of the outer edge a surface extends downward to intersect with a rearwardly convex surface which extends downward and inward. A central portion of the rear reservoir surface is recessed forward and inward.Drawings of the design are included wherein:Figure 1 is a right, top, front perspective view of a bidet embodying the new design;Figure 2 is a top plan view thereof,Figure 3 is a right side elevational view thereof, the left side elevational view being a mirror image of the right side shown;Figure 4 is a front elevational view thereof,Figure 5 is a rear elevational view thereof; andFigure 6 is a bottom plan view thereof.