When I had a stoma I got DLA but that might have been because my stoma at the time was not working properly. I had to spend several hours at a time lying down on a bed with the stoma off just moping up because my skin was so burned with the acid and bleeding and the bag would not attach, and I had to wait until it recovered and hope that a bag would stick on. This used to happen every few days and I was told it was very rare, but when I was in hospital and was talking to some other women they said it was quite common for people to have problems.
Mind you I did not get DLA the first time I had to appeal.