I. Rare but somewhat humorous misspelling of photos, with a misplaced apostraphe.
II. Excretement, particularly diarrhea.
III. Similar to phooey, phoo's is an exclaimation that may be uttered, or rather shouted by someone who is in a spot of bother, or is displeased or unpleasantly surprised by something.
IV. A polite and yet somewhat unusual replacement for any swear word you may wish to refrain yourself from.
I. "Ah took some phoo's terdeh, Ah did. Wiv mah frehnds."
II. "My little bon-bon Banbo and my littler bon-bon Banjorb have the phoo's, they do!"
III and IV. Georg, after realising he has not included doors when he built his house, exclaimed with slight annoyance at his little mistake: "Ah, phoo's!"