The whole setup consists of no more than switching the anti-siphon tube on the water-closet valve from draining into the overflow outlet there (3rd figure below) to a hole made at the back of the toilet seat (1,2,3 below) -2 to 3 feet of 1/4 inch O.D
vinyl or similarly flexible hose, and a carefully drilled hole -details follow below -minor changes necessary or optional, but really easy.
A DO-IT-YOURSELF BIDET
for One Slim Dollar Bill
[Note 1: There are certain small disadvantages or dislikes to this set-up, but if you have any brains at all, you will figure it out, get used to it and swear that this is 'the greatest invention since sliced bread'.
[Note 2: TOTO toilets are 'best rated' -really excellent!]