Rectal pain and pain relief question. Are acetominophen suppositories for treating anus or rectal pain?

Not necessarily. Acetomenophen, whether taken orally or per recum, is absorbed into the bloodstream and circulates to its site of action. There is no advantage to take the drug rectally if you have rectal pain because the drug does not produce its effects at the sie of administration.
No. Rectal suppositories are generally for those who cannot take anything by mouth.