Lorraine
I think the time has come to stop asking for advice from the forum and get some medical advice. When you read this message, I suggest you call LL HQ immediately and ask to speak to the medical team.
If for any reason they are not helpful, get yourself to a walk-in centre and see a Dr there if you can't see your GP. If that is not possible call NHS Direct.
None of us are able to give the advice you need. We are only people who have done the programme ourselves and all I can say is I've never had diarrhoea on LL - I have the opposite issue and I have now sorted mine out. Since it has been several days, you need to seek medical advice. You are probably dehydrated (which would explain the loss of 4lbs overnight). Don't take chances with your health!