What is the problem, when the screen becomes unresponsive?

I recently opened my iPhone 5s, It must have not got sealed again because about a week after the bottom half got wet around the circuit and it made hundreds of lines across the screen because of how it is designed which you don't see unless you get water in screen. Then the problem continued up the screen as the weeks went by. Now there's a spot on the right side where it looks like a circuit short circuited due to water, and I have to press on that spot for the upper half of the screen to become responsive to touch. The bottom half responds just has all them lines going across all the way up to where the water screen damage is. Now is that a digitizer and screen display part I need to buy to fix? Or is that a logic board? I'm thinking it's just the screen misplay and digitizer...? I don't want to buy the wrong part.