This is funny, but there is nothing funny about not being able to shit when you need to shit. I commend you for your courage in bringing this up, DG!
Due to my new geographic location, there are no Opioids (which I am extremely bitter about), and therefore no constipation. But another trick I used to use is/was twisting my torso around back and forth to exert pressure, which I figured out by many times going for the TP thinking I was finished, only to find that that turn and lean motion stimulated further motility quite effectively. Also, sometimes applying pressure with my hand or arm to my pelvis, where my intestinal tract lies beneath, would also help stimulate movement/motility within my bowels. I'm not sure whether it was psychological, or whether I was actually promoting movement through physical contact, but either way it often worked for me.