Go to my BYC page. the 2nd page there are some tables of signs and symptoms that may help. If the hens smell really bad then going by the other signs I would guess enteritis. I doubt it is worms because of sudden onset with too many birds at once. I'll say im sorry first....but I'll be blunt. You best bet right now is to cull all others that have had contact with the sick ones. When you have a sudden death issue of more than two hens like this you are usually asking for trouble and taking a lot of risk in trying to fight it. There is more than one disease that could cause this that is also transmittable to you and your family / other animals.