Sometimes I can feel when it is working and outputting. Not pain exactly, except for those times when I cut the faceplate just a wee bit too close to the stoma, and I can actually feel when the stoma expands to pass waste - right up against the faceplate! Do you think that might be what you are feeling? I do know that it is hard to describe the feeling of actually passing waste that I sometimes can tell. I guarantee you when doctors tell you there are no nerve endings in the intestine so the stoma doesn't feel anything and there can be no sensations coming directly from the stoma - they do NOT know what they are talking about! So. Pay attention to your body, and your stoma. Be aware of feelings from your stoma. They may not be the same as you are accustomed to from other parts of your body, and you may have to learn to re-interpret them as you get to know your little friend on an up-close and personal basis. It is possible that a confused nerve ending transmits a signal that SOMETHING is happening, and your brain doesn't know what it means, so interprets it as pain. That also happens when you have neuropathy, and some of the nerves try to grow back and send very mixed signals, so that slight pressure feels like pain to your brain. (Yes, my neurologist and I have had some VERY interesting conversations. What doctors DON'T know about your brain far outweighs what they DO!)
At any rate, I would venture to say that if you don't get very sharp pains when you are outputting, you probably don't have any real issue. If you check that your faceplate is not butting up tightly against your stoma, you should also have no problems from that arena as well.