"Rectal exam" as part of bowel-movement monitoring

Families of habitually constipated kids - have you ever done this - and if so, was it not so much checking for abnormalities e.g haemorrhoids, as simply checking for un-done dung?

And if so, have you ever had to use the dreadful "shock unannounced insertion" method.

In the history of this household, the parental - as opposed to doctor/nurse - "rectal exam" is usually just a method of inserting some evacuant substance (e.g liquid soap) and/or mechanical rectal evacuation (by finger, or with something) - because the result of the "exam" is a foregone conclusion.