I have heard anecdotally that CS is indeed effective when given rectally and I once recommended someone try it for a lower tract ulcerated sore that would not heal and was causing the body to produce it's own alcohol. The guy with the problem was ticketed for DWI due to his breathalyzer test and his family was accusing him of being a secret alcoholic, though he swore he did not drink. Either the rectal colloidal silver of some of my other suggestions appeared to work.
Certainly one of the obstacles in using colloidal or ionic silver for many conditions is getting it past the digestive system and the hydrochloric stomach acids that tend to break down the silver, especially ionic silver.
I can see no reason not to try it if you are so inclined. Let us know how it works if you do.