can riding a stationery bike cause hemorrhoids?

not the most pleasant topic to discuss...apologies. has anyone had an experience related to hemorrhoids appearing after riding a stationery bike? 

It does put a lot of stress on that area of the body.  I have heard that taking lots of long baths can do the same thing.  So it does make sense.

But, I can't tell you that I've ever heard of it before.

Sadly, quite common but rarely brought up. You may want to try a recumbent bike for a week or so to give the area a break. Also (depending on your workout outfit), steer clear of any thongs and wear full-coverage underwear so that there is less possibility of chafing. Obviously going commando in only yoga pants/shorts is a bad idea -- just like the workout socks that have two layers to prevent chafing, underwear and workout pants/shorts are equally good at preventing chafing. And obviously if your gym has sub-standard seats with little padding then that will worsen the situation.

Hope that helps.