Go to your local Health shop and get some linseed, and just sprinkle on your cereal, or alternatively make a past salad:-
use, pasta
onion
sweetcorn
tuna
cucumber
all mixed with a bit of mayo, works a treat!!!!
I had the same problem. Loads of water and get a bottle of Lactose syrup from the Doctors. You can also buy it over the counter. It was the midwife who told me to give it a go. Its really sweet but does the job.