Stomal bleeding should normally cease within 10 minutes if, after applying the drainage bag, an ice cube is held over the area of the stomal bleeding. If the bleeding does not cease in this amount of time and especially if you are on blood thinners, report to the ER. They may prescribe and teach you to use silver nitrate sticks to cauterize the area of stomal bleeding. The best way to control bleeding is to prevent it in the first place.
The second responder correctly stated that if the wafer hole is cut too tight, than it may cut your stoma, especially if the wafer you are using is not soft and is sharp when you cut it to fit. This is true if you have a stoma that protrudes at times and at others is more normal appearing, only 1/2" to 3/4" high. In this case, one needs to carefully note where the stoma begins and the skin ends. Basically this is at the discoloration line, or when the stoma appears more normal, not protruding.
John H. RN Enterostomal Therapist
Certified Wound & Ostomy Nurse CWON
in Graduate school for MSN education