Yes, you can cause your stoma to get dark. Make sure you are not cutting the hole in your wafer to small. If it is to small it will bang up against the stoma, which will mark it up and cause it to become dark. Some times it will darken up if you have stool resting on it all the time. Normally this will fade away if you take a shower, with no pad (try to time it when you think it's not going to squirt, and just have all your appliances ready when you get out of the shower), and lightly rub the stoma clean. I am guessing this issue is most likely due to wearing clothing that is to tight across your stoma. Try weary some sweats, or other loss clothing for a week or so, and you should see an improvement.
There is nothing irrational about freaking out about a stoma. It is your insides on your outsides for gods' sake :eek2: When it is healthy and happy it will look a lot like your tong, a little red with no marks or darkness. But, don't be surprised when you find some red blood, or mark on it. They normally show up from being active and the wafer just rubbing up against the stoma. I have had my illiostomy for 25 years. Soon after having the stoma I stopped wearing jeans, or tight pants, due to the fact it would shorten the life of the wafer by forcing stool out the sides, and it would cause the stoma to get damaged.
Don't be afraid to ask ?'s.
Peace and love.