If you want to become part of the Premier organization, but any definition, the WOCN is where it's at. The WOCN (Wound Ostomy Continence Nurse society) is the organization that creates the standards of care adapted by all nursing organizations and health care agencies (not to mention the standard for which care is held to in lawsuits). They continually create new standards of care to specific topics and offer national and regional conferences annually in which to participate. You have the opportunity to join committees and be a part of the large picture. They have created an entire evidence-based nursing practice. The physicians look to them as the experts. To join an accredited school, and it is easier now as there are quite a few online courses, you must have a bachelor's degree and so many hours of practice. Each arm of the WOCN - Wound, Ostomy, Continence is 3 weeks and with clinical time and professional practice, tack on some more, that you can do locally thru another certified WOCN nurse in the particular specialty. You need only take one, two or all three. Professional Practice is added onto each if needed, unless you have had a certification in one of the others already. Renewal is every 5 years by portfolio or retesting.
If you just want some credentials and your organization is willing to foot the bill, (about $3500 + expenses), you can get a WCC, which stands for wound care certified, which means you went through their class and exam to obtain their "certificate". In other words, you obtain a certificate, not testing through national certification. However, since WOCN nurses are few and far between, any training you can get to help patients, by all means, go for it.