Ulcers on my stoma...HELP

I had colon removed in 2011 due to ulcerative colitis. They have looked for crohnes and it was negative. Well last night I notice an ulcer on my stoma. Today it has grown. I've been using my stoma powder on it and it's not helping. The stoma is swollen and painful. No blockage. I don't know if I should wait until Monday or go to ER? I don't know if this is crohnes or not. I'm freaking out. Please help.

Turns out the lesions is salmonella. Went to ER today. Because the ostomy clinic moved out of town. So on Levaquin antibiotic. A normal person wouldn't need antibiotics, but with an autoimmune problem is different. Thanks for listening and hope this helps someone else.