I think that if your Doctor is being so dismissive of how you are feeling then maybe you would be better off finding a different Doctor.
When you say you feel a "pinching feeling", is it painful or just "weird"? I ask this because when I first had my Ileostomy I used to get weird feelings,like a sort of tightness when my stoma was active but it either went away or I have just got used to it and dont notice it anymore. If it is actuely pain that you are feeling then maybe you do have some sort of a partial blockage. Are you drinking enough fluid to alow for the food to be pushed through your system properly?and always chew chew chew your food well.(I learned this to my cost with a partial blockage,ouch.)
I was told that with an Ileostomy the intestines do a sort of right hand turn before it comes out onto the belly,so when you think about it the food passing through has a more difficult time passing through the intestines than it would have before when it just went straight down.And that is why we are more prone to blockages. It's only happened to me twice in nearly 3 years though and each time I new it was down to me not chewing properly.
I have been told that it is not possable for us to feel pain in the stoma(no nerves or somthing,I am not sure) so although your pain is real,I would say that it is a sort of refered pain from around the stoma area.
I hope that made some sense. If you are in pain and not able to get on with your life because of it then you are within your rights to find a Doctor that is going to listen to you.
I hope that you feel better soon
Sue