Food and water are necessities. But what to do when you need to get rid of what you ate and drank?
It is best to have a standard place or method for your eliminations. It all depends on where you are. In the city, use a toilet in a bathroom or washroom. If you are in the country side, it is a little more complicated.
For a long-term solution, or a permanent camp ground, a dug latrine or outhouse is good. A squat hole for a place you go to often but do not keep up like a standard campsite has less work to it, but is only really good for one or two people for short periods of time. Cat holes are of the moment pits you dig, use and then cover up again.
But what if you cannot leave your waste? A portable bucket is a good solution.
Take a 5 gallon bucket, with a handle preferably, from detergent or bulk food storage. Double line it with trash bags with some baking soda and charcoal(from fish tank filtration) in the bags. Twist the bags at the top and you can use the lid to keep them sealed. If it is something you are taking with you, use a large sealable bag to put things like toilet paper, hand sanitizer, a gallon of water and some vinyl gloves. Since it is all disposable, once you get to a place with proper facilities, you can just dump the full bucket if you want to.
There are some camping/caving supply places that have bags that are made especially for when you void yourself in ecologically delicate places. Make sure you find out about prohibitions like that before you go into caves or other places like that.
Knowing how to do this can help in other situations. Check out the Excersizes.