Switchable:
I realize that not all cases of marks in the panties are due to withholding, and after I was finally broken of the habit; any further marks in my underpants were indeed due to my 'carelessness' at wiping. However, my original condition was, I guess, psychological. At that time, I had the habit not only of ignoring any urge to defecate, but when my body wanted to (because as you said, inevitably it came to that), I would find a quiet place, stand perfectly erect, and scrunch my cheeks, and exert myself (squeeze) to drive the turd back in, and usually, I would succeed; but inevitably, there would be some remains on my ass, and in the back of my underpants. I did this because I was asserting my control over my functions. Of course, as we become more aware of the facts, and understanding and accepting of things that 'willpower' just cannot overcome, this appears a silly thing to try. But I used to do it. Remember, I was only 4, 5, 6 at the time (So I was a slow learner ๐, sue me, or if you'd rather, give me an enema). Occasionally, I would have to let a little pebble of crap fall down the leg of my pants; discretely kicked aside onto the lawn, or into the flowerbed. (Obviously, I was real brat.) Obviously, there were traces of poo in my underpants as a consequence. So the marks in my underpants were indeed consequences to my intention of 'withholding'. I don't know of any other cases as extreme as this, although I have heard of some interesting things in RL. I sometimes wish I had that same degree of control over my anus as I had at that time.
Now, as to whether Mum's 'therapy' constituted abuse; well, what kid doesn't feel that being given an enema is 'abuse'? At that time (late 40s, early 50s), the abuse argument coming from a kid would have got Nowhere; then, a parent was always assumed to be doing what was best for their kid. Then, child abuse was assumed to involve more physical activities, such as beating, sodomy, cruelty oriented activities; usually involving non parental figures. Cases such as kids being abducted, tied up, whipped, sexually molested, etc. Yes, they did occur; rarely was a parent the culprit. What Mum did to me was meant to help me; and to a very large extent, I believe that it has succeeded.
Finally, from your rather assertive response, I fear I might have touched on a nerve, and if so, I deeply apologize.
C.