... What is nupercanal? ...
Let me google that for you:
Generic Name: dibucaine (DIE-byoo-cane)
Brand Name: Nupercainal
Any 1% dubicane ointment or cream should work. The cream might be easier to spread and work a half-inch into the rectum, but it feel wetter.
Brands vary in cost, shop around. Buy multi-packs.