Aegh

Aegh is derived from the misspelling of 'Argh', but once said aloud, aegh has pleasing results.

With heavy pronunciation on the 'gh' at the end of the word, it sounds your disgust far more appropriately than 'argh' ever could. Can be used to mean the same as 'rage'

Bryony: Once you get married you'll realise that the fighting isn't childish.
Lauren: AEGH!