Stimulating The Kitten
Very young kittens cannot eliminate without help and the mother-cat licks the kitten's abdomen and anal area to stimulate elimination. You need to mimic this action after every feeding. You can even do it a bit before each feeding as well.
Prepare a bowl of warm water and some cotton balls, tissues, gauze or a soft cloth. Dip the cotton ball into the water, squeeze out the excess and, using a gentle circular motion, massage your kitten's abdomen and anal area. His natural response is to eliminate urine and stool. Don't worry if he doesn't pass a stool after every feeding or even every day. Keep stimulating until he stops eliminating, though it's important to know when to stop, because stimulating your kitten for too long can make his delicate skin sore and raw.
Another method is to stimulate the kitten over a sink. Put a bowl in the sink to catch the waste and start a steady trickle of warm water at the faucet, keeping the faucet away from the kitten. Run the water over the cotton ball, squeeze out the excess water and stimulate him as above.
Or, you can simply place the rear end of your kitten into the gentle trickle of warm water (make sure it is not too hot!) and then start stimulating the abdomen and anal area. He should let loose and eliminate quickly. Then wrap him up in a warm towel and keep him close until he is fully dried.
The consistency of the kitten's stools will give you an idea as to whether you are feeding him the right amount and strength of formula. Normal stools have a toothpaste consistency and are a yellow, mustard color. If the kitten develops diarrhea, you may be overfeeding or the formula may be too rich for his digestive system. Try diluting the formula.