I think poop doesn't smell as bad when animals are on higher quality food. If you don't know what kind of food I mean, you could make a thread asking about grain-free food, or better yet, check out the threads that are already in the food forum.
My last dog arrived on crappy shelter food (Science Diet, I think) and his poo smelled absolutely terrible, and he was gassy. Once he was transitioned to better food (I fed him mostly Innova EVO, but also wellness core, solid gold BATM, orijen, and taste of the wild to give some variety) his poop was less smelly and he wasn't gassy anymore.
I've heard people on here say that raw diets make poop less smelly, too.
HaHa, I agree with the above posters that poop is well...smelly! However, the thing I have found that has worked the most for my 3 is probiotics/enzymes added to their food. Seems to help with breath, too! Some good brands that I like are: Ark Naturals Gentle Digest (probiotic), Solid Gold Seameal (enzymes), Prozyme (enzymes), Animal Essentials (probiotic/enzymes), Wholistic Pets Canine Complete (probiotic,enzymes), Missing Link reg. or plus (enzymes). These are just a few of the brands out there. Some people use yogurt or human probiotics supplements, too. Good luck!