I use an eakin seal for this problem. It's a ring of sticky stuff that goes around the stoma and protects the skin. When you put one on, it will make a barrier between your output and the irritated skin, and it won't itch (and the skin underneath can heal).
You can get free samples to try.
Also make sure you're measuring your stoma every time you change the pouch this close to surgery. It shrinks, and if the hole is cut too big, then you'll have more contact around the stoma.
48 years old, female.
2004 dx indeterminate colitis. Back and forth between Crohn's and UC dx. Many drugs, minimal success.
2010-11 Crazy skin and eye complications, high fevers, bad flaring. Out of good drug options, tired of scary drugs.
Feb 2011 -- proctocolectomy with permanent ileolostomy; abscess, blood clot. Still healing, still glad for the surgery