bag before or after placing barrier?

I got my colostomy a month ago, was in hospital with more surgery until last week.

My hospital ostomy nurse said always place bag on barrier before placing on skin, but visiting nurse said to get fit right I have to place barrier first and snap bag into place.  She did this yesterday and my belly still hurt the rest of the day and today, a lot, despite meds.

I find it difficult to get the barrier sized and shaped just right - odd shape and on an angle across a dip from previous surgery.  The one I put on before the nurse came had too big an opening.  The skin was not irritated after 3 days, but it showed a tiny bit.

I understand the stoma will change size and shape for a while.  The visiting nurse cut me a template for the opening so I can check it for size and shape. 

Should it hurt so bad to push the bag into place?

 

I never had pain from putting the bag on. What brands and items are you using?

Thanks for all the replies!

I'm using the Convatec Natura, with convex seal (can't imagine this big yellow thing as a "wafer.")

Maybe the severe, fairly deep pain is because I'm only a month from getting this rig, and then there was a second surgery, open this time, to remove a blockage and some pieces of small bowel.  It still hurts a lot today from the nurse pushing the bag on yesterday. 

 

Thanks to everyone for the advice! I like the bags with the gas-release and using cooking spray works a treat. I taught the nurse the soap on the ring trick to make it easier to snap things together.

My stoma changed to quite an elongated shape and is now too short for the wafer. I knew it was going to be a learning curve to try the Eakin ring thing, so I waited until my visiting nurse came today and helped me with my change.

I feel confident I can do the changes myself now, but doing this job hurts my reoperated shoulder a lot. I have to pull my bad arm across my belly in the one direction that is painful. I take a pain pill half an hour before starting but need to lie down because of the pain when I am finished. My insurance wants to cut me off from this one thing where I need help (wish they had someone to cook because that hurts too). Nurse says she may be able to come one more time. I won't be able to get the belly surgeon to write for more - seeing him in a couple of days. I'll ask the orthopod next week. Not too much hope for that though because he said (call to nurse) it's OK for me to use the arm to do the job although I'm still sling-bound and allowed only passive motion. I do wonder if he has any idea how painful it is. I am concerned I may be doing more damage to whatever he reattached.