My mother had a colostomy back in october 2012..all has been going pretty good til today, and her stoma is swollen and enlarged....what might cause it?

Hernia or prolapse: Either a hernia or prolapse can cause this. A hernia means that the internal opening through the abdominal wall for the colostomy has stretched out and other tissue is getting stuck. A prolapse means that a portion of the colon is sliding out of an otherwise appropriately sized hole. Laying flat with the knees bent and gentle pressure on the colostomy can help it go down. If not, see your doc.

Swollen stoma: Maybe be constipation or possible a stomall hernia. Should get it checked out by her surgeon.