Just what is meant by Irregularity? ?

if its a condition (real or imagined) of the bowels, then i suppose diaetetic could mean diatetic.

but I have never heard of trepanning used for this.

(and goodness knows, americans seem to have a fascination with clean, regular bowels, that has gone excess many times in our history, witness, Dr Kellogg's Spa, and the still current "high colonics" fad.)