Yes, I've had a similar thing happening to me another month and indeed slightly injured myself in the hip.
Well, I've adjusted my food intake for the upcoming days. About the same as I always eat on the low days but substantially less on the high days and cutting out most of the extra carbs. Just fruit. I've read a really, really intrigueing article by dr. Michael Eades, whose words I kinda see as the gospel :
http://www.proteinpower.com/drmike/?p=274#null
It's on whether fiber is really all that good for health. Fiber damages the linings of the gut and makes it produce mucus. What if you're already having an overly sensitive gut (like me & ljk) and produce PLENTY of mucus to start with? Not really smart to irritate the gut even more, isn't it?
That made me rethink my food strategies and try out another fiber strategy. Instead of aiming for 25g or more, I'd rather aim for 15-25 g which seems to keep me 'regular' without needing tons of TP, if you get my drift. And cut back a little on the grains (not quinoa, which is a seed) and increase the fruits again!