People who think they are always right and ram their opinions down your throat. No-one knows everything. Those who shout loudest are usually the ones who actually know the least.
It could be any number of things. Until your doctor is back I'd try keeping a food diary. That way you can try and work out if there is a any pattern between what you are eating and the cramps. Might also be worth using this diary to record when you are feeling stressed etc.
Definitely go see your doctor when he is back. Fingers crossed you get things sorted soon!
Customer helplines that use recorded menus that promise to put me through to the right person but never do - and being ill. Oh, and did I mention customer helplines :)
I feel as others have said Swimmer, its something to see your doctor about, and if yours is still on leave then seek an appointment with another doc at the practice, assuming its not a one doc surgery. Are there any of those left?
Its probably nothing serious but if I were you I would definitely get it checked out.