If you are squeamish, this thread probably won't be for you. My apologies in advance.

In The Spanish Holocaust, Paul Preston makes note of many prisoners of the Nationalists being forced to drink castor oil. As it is a laxative and the prisoners were subsequently paraded through town, the resulting condition was embarrassing and degrading. (edited to add the following sentence) This punishment is mentioned dozens of times in the text, and apparently was used in many regions of the country in 1936 and onward.

Now, I had never heard of this practice prior to this book, or at least I don't recall hearing of it. Was this a uniquely Spanish punishment? Was it confined to the 1930's? Or was it more widely used? Did other groups in other countries (or other times) employ this degrading tactic?