Crohns and Colitis UK have just published an information sheet on dehyradation which is very useful. I am struggling to remain hydrated at the moment with the hot weather in the UK.
http://www.crohnsandcolitis.org.uk/.../Publications/Info-Sheets/dehydration-ed4.pdf
http://www.crohnsandcolitis.org.uk/.../Publications/Info-Sheets/dehydration-ed4.pdf