Not sure what your shower looks like, but in my last camper I replaced the angled rod with a flexible one. This resulted in a bigger shower area, allowing me to take a shower w/o getting tangled up in the curtain the entire time.
As the above posters said, just a couple small holes left behind from the original mount brackets. You can fill them in with caulking or putty (although I didn't bother; you can see the holes in the 3rd pic)
2013 GMC 2500HD Crew Cab SLT 4x4, 6.0L
2016 Jayco Eagle HT 29.5 BHDS