[57] Then the Blessed One, having stayed at Sāvatthī for as long as he wished, set out on tour toward Rājagaha. Wandering on tour by stages, he arrived at Rājagaha. There the Blessed One dwelt at Rājagaha, in the Bamboo Grove (Veḷuvana), the Squirrels' Feeding Ground (Kalandakanivāpa). Now at that time a certain bhikkhu was afflicted with a fistula (bhagandalābādha). The physician Ākāsagotta was performing surgery (satthakamma) [upon him]. Then the Blessed One, wandering on a round of the lodgings, approached the dwelling of that bhikkhu. The physician Ākāsagotta saw the Blessed One coming from afar; having seen him, he said this to the Blessed One: "Let the honorable Gotama come; let him see this bhikkhu's anal passage — it is just like a monitor lizard's mouth!"
Then the Blessed One, [thinking,] "This foolish man is mocking me," turned back from that very spot, and on account of this occasion, in this connection, had the community of bhikkhus convened and questioned the bhikkhus: "Bhikkhus, is there a sick bhikkhu in such-and-such a dwelling?"
"There is, Blessed One."
"What, bhikkhus, is that bhikkhu's ailment?"
"That venerable one has a fistula, venerable sir; the physician Ākāsagotta is performing surgery [upon him]."
The Awakened One, the Blessed One, rebuked them: "Bhikkhus, it is unbefitting of that foolish man, unsuitable, improper, unworthy of an ascetic, not allowable, not to be done. How indeed, bhikkhus, could that foolish man have surgery performed on the private parts (sambādha)? On the private parts, bhikkhus, the skin is delicate, a wound is hard to heal, the knife is hard to manage. This, bhikkhus, is not for the confidence of those without confidence …" Having rebuked them and given a talk on the Dhamma, he addressed the bhikkhus: "Bhikkhus, surgery must not be caused to be performed on the private parts; whoever should have it performed commits a grave offense (thullaccaya)."
Now at that time the group-of-six bhikkhus, [thinking,] "Surgery has been prohibited by the Blessed One," had vatthikamma performed. Those bhikkhus who were of few wishes … took offense, criticized, and spread it about: "How indeed can the group-of-six bhikkhus have vatthikamma performed?" Then those bhikkhus reported this matter to the Blessed One.
"Is it true, as they say, bhikkhus, that the group-of-six bhikkhus have vatthikamma performed?"
"It is true, Blessed One." …
Having rebuked them and given a talk on the Dhamma, he addressed the bhikkhus: "Bhikkhus, neither surgery nor vatthikamma must be caused to be performed within two finger-breadths around the private parts; whoever should have it performed commits a grave offense (thullaccaya)."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.