Apparently the skeptics have never tried a Graves speculum, as I have. I acquired many instruments from a retiring doctor, He had 2 Graves speculums of various sizes. I stuck all of them in tmy rectum, including the largest ones he had. I didn't injure myself and didn't wind up in the ER. I did start small, then found it easy to insert them with blades closed. One then opens the blades with the screw on the side or pressing on the lever The end of the speculum is adjustable so one can make it larger. screws hold the size. After insertion with the blades closed, one pushes gently and there is no pain. An adjustment on the handle can make the outer opening taller--better adjust it before insertion, The largest speculum I used had, at the outer end, a diameter of 2" x 2.25" The blades are about 1.5" wide. The longer lower blade is about 5.5" long. Lest readers not believe the size, there are many photos and videos of persons being fisted, that is the whole hand being inserted, without damage. I cleaned myself out thoroughly, used lots of lube, gloves, newspapers to catch the mess, and mirror and flashlight to look.
All that said, I didn't get any big charge out of enemas, the proctoscope, stigmoidoscope or anoscopes or speculae. so I experimented with the toys only for a month and don't use them anymore.