I've used this thread along with other reading to come upon what works for our bulldogs. So I figure it would be good to share our experiences.
Zuki was started about a year and four months ago on raw. We got her at 8 weeks and she had the "rhea" basically her whole life up until about 9 months old. We tried kibble after kibble, and couldn't find anything that helped, more protein, less, no grains, staying on one decent kibble for 4+months, but it never made a positive difference and just kept getting worse.
So I finally had enough and gave her tract a day to rest, then started on "home cooked" the next day. Scrambled eggs and pumpkin for a couple days. Evened her out, then we made a vegetable mush, cooked chicken, eggs, and supplements for a bit. We found this time consuming but it worked fantastic. She loved it and for the first time in her life she had good poop for an entire day. We decided to switch to raw to make it less complicated as far as supplements go. So now she has whole chicken/rabbit, organs included(gutted and skinned/feathered) and her coat is fantastic, she keeps easily trim and has much better water intake, great teeth, no dog smell or dog farts. She's about 45 lbs for the winter and more like 42 for the summer when she is in better shape.
Pic in action this summer:

Then on to the boy -
We got him about 8 months ago. He was on a crappy kibble, so we slowly switched him over to a good kibble. No grain, lots of protein. He did ok on it. He was overweight when we got him, so we were able to slim him down and had enough exercise to give him some more muscle. Once he was switched over completely he still had a very greasy coat, and a pretty doggy smell, his poop was ok, very large and numerous. He got the big "D" prolly once a week on the good kibble.
We finally decided to switch him too. Between eggs and pumpkin to help him settle his stomach on the switch and the chicken he is doing great. Within 2 days his coat was much better, not greasy and softer. He did have some diarrhea on the switch, but the egg and pumpkin has been doing it's job. Had to teach him to chew, which really just took hard freezing the food and hand feeding him while making him slow down between bites(sitting/working for his food). Kibble fed his whole life(about 4 years old when we got him) and took about 2 days to teach him to chew. I don't think I have any good pictures of him now, need to get some but here is before the switch in the summer leaned out a bit:

Costs are fantastic. We get cases of leg quarters for filler between the whole more prey model for .40-.50 cents per pound. Then we get whole chicken(minus feathers, stomach and intestines) for .85 cents a pound and rabbit in the same condition for 2.00 a pound. This is from a local(<50 miles) farm. Bought a nice chest freezer to reduce trips. They both eat about a pound a day, give or take depending on the season/activity level. Kibble for the boy was 60 bucks a bag and he ate about 2.5-3 cups a day. Feel free to pm me if you have any questions. We do "large screen" blood tests yearly to check some of the levels.
Nate