If your talking about the wall butted against your tub it is a common issue.

Tile person should run at least on row of tile or extend tile 2-4" beyond tub. They should also use waterproofing on that wall extending again onto that wall. The lower section of that sheetrock extending from the tub should be waterproofed about 12" from the tub under the molding. The molding itself should be waterproofed or painted with an oil or exterior paint on ALL sides.

The corner at the base of your tub is one of the worst water collection spots in a bath and often overlooked in waterproofing. Water pools on tub corners and migrates down. If caulking from tub to walls fails or is done too soon water will migrate behind the caulk into the wall. Most color matching caulks are not silicone. Water migrates down from the thinset drying. Tile persons caulk next day and that moisture gets trapped behind the caulk which isn't water rated. The caulking fails or looses its adhesion. The water then migrates to the area your complaining about.

It is not uncommon that when the caulk from the tub top corner to the floor along that wall is cut water will literally run out as it gets trapped.

They sell corner guards for tub corners. Check the caulk and redo if needed. Unfortunately once sheetrock gets wet it can mold and deteriorate. It can only be permanently fixed by replacing.

I love shower screens and that IMO is what you need here.

Please post some pictures.

acm There was new plumbing and it is an interior wall, We have the best fan we could find with a great draw and run it during and after shower til the mirror is clear. We also have a window in this room. It was determined during the remodel that all of the drywall was wet which caused the mold. Thank you for your input.

wannabath Thank you for your input. I am going to contact a tiler and see what they can do about all this.

Without a photo I'm not sure, but sounds like same problem we have: the tub isn't perfectly level, so after a shower when water runs down the tile walls it collects (in the tub 'channel' below the flange that is behind the tile) and runs towards one front corner of the tub. The wall there (which is plaster - i.e., the entire tub surround is tile, but inside the room is painted skim coat plaster)) has been water damaged the entire 14 years since we gut renovated this bathroom. A pro GC did the work, all inspections/permits passed. Our solution is to have (another!) GC jack the tub level, then re-tile the tub surround and repair floor tile next to tub. So we're ignoring it for now.

ap999 My DH thinks that might be the problem too. I guess we could get a second opinion and then go back to the original GC.

Shower could be leaking in the wall because it wasn't twisted on tightly enough. That's a nearly free fix. I'd try that first.