How old is baby/child?
I would add enzymes to the food to help it break down further. I have a new favorite brand http://www.gallbladderattack.com/pro...gestplus.shtml
The capsules are small and I break them open and sprinkle about 1/2 capsule on DD's food.
One thing I thought of is slow transit time. The amount of time between eating and pooping is transit time. The longer it is, the more opportunities to increase fermentation and rotting of the food. One way to experiment is to add a few corn kernals or carrot pieces as these may travel through your system and exit exactly the same as how they went in. That way you'd have a good idea how long it is taking food to travel. In my reading it should be < 8 - 10 hours. Some say quicker than that. However, if you feed babe corn on Monday and it comes out on Wednesday or later, I'd say this is a very good reason for smelly poop.