Pile(s) dream meaning is explained below using 3 different sources. Each interpretation is shown with its source.

Interpretation 1 — Stearn Robinson - Tom Corbett

If you dreamed of putting things in piles or of seeing piles of things, you are being cautioned about a forgotten (or neglected) obligation which could suddenly embarrass you; don’t compromise your integrity for the sake of passing pleasures.

For the physical condition, see Hemorrhoids.

Source: The Complete Guide to Interpreting Your Dreams Author: Stearn Robinson - Tom Corbett

Interpretation 2 — myjellybean

If you dreamed of putting things in piles or seeing piles of things, your dream is warning you about a forgotten (or neglected) obligation which could suddenly embarrass you. Take care of what you need to, and don’t compromise your integrity for the sake of passing pleasures.
Source: My Dream Interpretation Author: myjellybean

Interpretation 3 — Stephen Girard

Dreaming that you pile anything against the wall, denotes assistance in business. 
Source: The Mystic Dream Book Author: Stephen Girard