My surgeon told me that she would work with me to locate a site for the stoma.  She got busy and never did.  She told me later that while I was on the operating table she asked the male nurses etc. where they would put the stoma relative to the navel and belt line.  I guess that they answered correctly and the stoma was located in a "good" spot.

I have never tried to wear the bag horizontally, just doesn't seem right to me.

Glad to hear they got it right, a small detail but a major problem if wrong, The bag side ways does seem odd but it seems to be popular. i can see from watching the reviews and vids why folk do it

I met the WOC nurse before surgery. She pointed out four potential sites. two near level with my belly button and two lower on my abdomen. I chose either of the two level with my navel because I worried the bag would be in my way or difficult to see. I've got a round little belly and frankly could not see either lower site easily.
Sometimes Oscar is in the way depending on the style of pants I wear. Some styles I can't get a good idea because I still need to gain 20lbs back. If ya have some spare weight laying around I'd accept donations...

My stoma is about an inch down and 2 1/2 " away from my belly button . Its where my Dr. just told me he was gonna put it not having a clue anyway at the time I just said ok . But seems to have worked out pretty good there as far as pant line goes no problem . Only little hitch is I use a 2 1/4" barrier so the edge of the adhesive part tends to go about half way into my belly button and sometimes doesn't want to stick quite like it should .   I wear a 12" bag and it is just right to tuck the bottom of my bag into my shorts or pants and let it just kinda roll over . Actually helps support it . I have tried sideways and up n down either way works ok . 

Will have that in the post to you first thing Monday morning.

It seems such a small item at the time but the position of the stoma does have a big impact on our lifes, a well sited stoma could mean the difference between a patient coping or having lots of trouble. I wonder from the posts do all surgeons realize this

Stoma site marking is so important (I'll have a video on that soon), and it can really make or break someone's experience.

I wear my bag sideways quite often (pretty much every day) and it works well for me. However, if your stoma is too low and your belt line will be across the bag when it's sideways, it may create more problems than it solves. 

Bago, that's a huge shame that your doc didn't mark the site before the surgery, but I'm glad things worked out for you!