My shower drain leaks. The water flows down the drain pipe and leaks at the elbow. I do not know if the pipe has a hole, or if the drain connection needs more calk. What shall I do?

Since you didn't say I'm going to hafta assume that you have a manufactured shower base and enclosure and not a custom tile shower. Before you start to tear things up Check the putty seal under the lip of the drain. If the shower floor gives a bit when you step into it then the base wasn't bedded min properly and that can cause the drain seal to rupture. The solution to this is to loosen the drain lip and force plumbers putty under the lip of the drain. Tighten it back up, remove the excess puttyand see if that doesn't stop your leak. If that don't get it click on back. Good luck, Tom