Mi screen not working right iPhone 4S

When I open some apps like the camera, temple run, draw something, and many others, it opens correctly the apps, but it has some defects on the screen. Some little coloured bars (1cm wide x 0.3 cm tall) appear in the screen. There may be up to 5 or 6 bars disposed in a horizontal way. They appear from bottom left to upper right of the screen. It's very difficult to explain. If someone understood what I mean, PLEASE answer me.

Thank you!!