A strange, high pitched sound first disturbed my sleep and then woke me fully. It was quiet, irregular, and I couldn't place it. I lay awake waiting for it to come again so I could work out what it was...
It came again! Like a brief, high wine that trailed off intermittently...
It was my stomach gurgling.
My stomach making a sound woke me up.
(This is still not as impressive as the time my friend was woken by a particularly smelly fart by her husband)