For number 1's I can highly recommend using an empty water bottle....and yes I am speaking from experience! Had to do just that during a 5 hour x-country in a C172! The guy I went hour building with laughed for 4 days straight when I told him what I'd had to do....until on the 5th day he got caught short and found himself returning home with a lovely yellow water bottle!
A word of advice though....if you're the only one onboard, as I was (thank god) then please make sure the aircraft is well in trim before attempting the manouevre.....a cockpit that smells like an old people's home is not a nice place to be!
For number 2's.... well I would grab your chart, look for the nearest suitable diversion and get down asap. Number 1's mid-flight is one thing and actually makes for good banter but fouling yourself is something you'll never ever live down!
Best of Luck whatever you decide!!!