Strange question - I have heard of people using poppers (Amyl nitrate) to help passing stools. Anyone heard or used this?

No, I haven't heard of this but will be interested to see what replies you get.
I did ask my GP for Valium immediately after the operation to have my piles banded, skin tags removed and botox injected because I was so tense anticipating pain before bowel movements, that I think the tension inhibited the passing of the stool. The GP said it was an unconventional use of Valium, but prescribed it anyway. I just took a pill immediately on waking, so that I'd be relaxed by the time of the bowel movement. It's also a smooth muscle relaxant apparently. I didn't take any further pills when it wore off. I only did this for about three days post op, then had the confidence to go without it!