What about tight foreskin or phimosis?
A guy from the forum posted this:
Please please offer this link to other young men suffering from tight foreskins and frenulum breve. There’s a LOT of misinformation out there and properly applied stretching will cure 99% of problems – if indeed they are problems.
Not even doctors are aware of this, and most still recommend circumcision to clueless guys.
Another page with a picture: https://phimosisjourney.files.wordpress.com/2014/11/method8.jpg