Patients will refuse all sorts of stuff. Patients have a right to refuse, however they must competently refuse. Determining competency is easy explain the risks and benefits of not performing something vs performing something and then have the patient repeat back what you told them in their own words. Most people that are refusing to get cleaned of their own excrement aren't competent to refuse to get cleaned up. As others have said it's worth investigating why someone is refusing something, but in cases such as refusing to get cleaned of excrement it isn't likely to be productive.