We've always camped with three kids and we'd never be without a toilet when away - to save on those late night sprints to the toilet block.
To help we've halved the cost of our Loo To Go to £9.99. http://www.olproshop.com/products/loo-to-go-portable-toilet
We sell a lot of these so I'm sure there are plenty of likeminded campers out there. Just use with a little bit of toilet fluid and water to help with stinks etc.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.