You can either purchase disposable enemas from the chemist, or you can use a reusable, which is basically like a large syringe which you fill with warm soapy water. Whether you're using the disposable or the reusable ones, the emthod of use is the same. Inject the liquid. Walk around for a bit, trying to keep it inside for as long as possible. Eventually, once you feel you can hold it in no more, empty your bowels in the normal way. This is standard procedure before undergoing any rectal medical exam, so can be relied on as a safe method.