Generally Rape isn't covered in the textbooks on torture to the extent of other methods.
Part of the Taguba report on Abu Ghraib includes comments that one of the translators raped five or six teenage boys, while a female guard took photographs. These must be in the pictures that have yet to come out from the investigation. Any idiot can face a crisis - it's day to day living that wears you out.
You had mentioned and have since elaborated upon the connection between abuses characteristic of the US prison system, past and present, and the use of torture by US authorities in occupied nations, prison camps, and like circumstances.
Rape is a form of abuse reportedly very common in US prisons. It is so much a part of expectation based on popular culture of movies and TV that it seems to constitute a broadly accepted form of extra-judicial punishment.
The tacit acceptance and even approval of prison rape in the American public seems to me related in some way to the tacit and even enthusiastic support for torture. There may even be a common base in racism, although I can't quite see what it is.
That's what I was getting at: not that rape is a form of torture used for extracting information, but that it is a form of degradation used to inflict punishment and establish or maintain dominance relations. And these are the main purpose of the institution of torture, according to some I have read. Extracting information is seldom the real purpose, which is why discussions of tortures effectiveness in that respect are moot. Torture (and rape) are very effective at their actual purpose which the instillation of terror.
