Flange
A "Flange" is the name commonly given to the sticky base plate of a two piece ostomy pouch system - in other words, the bit that sticks to the skin, that the pouch clips or sticks on to.
A flange's design and features can vary dramatically from company to company, and the products degree of comfort and success at sticking to the skin is improving exponentially year on year. That said however, the flange's success rates in these categories is very much down to the individuals own skin and personal tastes. What suits one person down to the ground, may not suit another person at all.