Great achievement comes from trial and error

 The young doctor was considered a budding genius for his experiments in the operating room, but the tools he developed took on a sinister look and the hospital administrators heard rumors that he was performing unauthorized procedures on young men he paid to undergo operations. After he was cut loose from the hospital, he set up his own laboratory where he could apply his tools without oversight. And if working over a subject didn't go well, the young volunteers could be disposed of without consequence. His latest invention is designed to deeply explore and expand a patient's rectum. This is a prototype, and it has to be reduced in size to be practical.  But the doctor may try this model first using a lot of force.