Hi Lucy's mom,
I just wanted to let you know that I was diagnosed with CF at 2 weeks old and it sounds like your baby is having some of the same problems I was having. I couldn't keep on weight and everything I ate went right through me. It got to the point (I was told) that as my mom would feed me it would come through me before I was even done! The stools sound about right too. I obviously couldn't tell you if your daughter has CF but if it was me I would get the sweat test done for CF as soon as posible. The sooner she gets diagnosed the sooner she can be helped and hopefully put on weight. I know my mom said that she knew something was wrong with me but the doctor kept telling her she was a nervous mother. He didn't send me to a specialist until I got down to a scary weight. Don't wait that long! A mother's instinct is usually correct.
I truly hope that it turns out to be something minor but if it is CF please know that it is not the end of the world. My mom was told I wouldn't live to see 20 and I just turned 30!
I wish you the best of luck. You and your daughter will be in my thoughts.