Yeah, managing megacolon is all about controlling and minimizing the symptoms to keep the digestive system running as smoothly as possible and try and prevent stasis.
With megacolon, the nerves that control contraction and movement, are either damaged or not formed properly. As a result the rabbit will have really large and small fecal poop, as well as oblong poop. The rabbit will also commonly have some mucous in the poop at times because if this disfunction. There can also be splats of poop that look like cow piles, but I would think that this would have to do more with the cecum also being affected. It's really hard to know the exact symptoms and everything involved, because there is so little information about it, especially in rabbits.
I'm fairly certain my bun Toby has it. He's a dwarf hotot, so has the spotted gene that it is suspected to be genetically associated with. I saw symptoms of it at around 4-6 weeks old. He has the typical large, small and oblong fecal poop, but not mucous as of yet, or cow pile poop. So at this point he seems to have a mild case of it, which I manage a bit with his diet. He does fine with a small amount of pellets, but not too much or he starts to get soft fecal poop. He seems to have better shaped poop with some pellets than without. I've tried no pellets and his poop got very large and a bit log shaped.
My bun Zeus may also have megacolon, or something similar to it. I'm not sure if he has it genetically or if nerve damage occurred from him having stasis, as he developed stasis right after I first brought him home and am not absolutely sure if his poop was normal or not before that. I believed it was. So after having stasis several times, I discovered it was his pellets continuing the problem. Once I stopped pellets he didn't get sick again. But he had the typical large, small, and irregular shaped poop associated with megacolon, though not really so much of the oblong shaped poop. And any time I have tried to reintroduce pellets, his poop shape has gotten much worse. So I manage his digestive problems with diet too. Where Toby can have a bit of pellets and does better with them, Zeus doesn't. So Zeus has been on a hay and veggie diet for about 18 months, and has been healthy and hasn't had stasis problems since.
What managing the diet does is keep the digestion as stabile as possible, and ensuring good gut motility. Because the nerves don't function correctly and there are problems with the contractions, this causes a back up of the poop, and so you get the odd shapes and sizes. Lots of non digestible fiber seems to help with this motility issue, to some extent, as it's not good when things slow down too much in there and start getting even more backed up than they already are. Hopefully I've explained it so it makes some sense
Along with diet, gut motility meds are sometimes used as well, but with my two, they have been stabile enough with diet that I haven't had to use meds.
I'll see if I can find any links that can better explain it, though most of the info I have read on it has been on forums from other rabbit owners.
Here are a few pics of what my buns poop looks like. First one was trying Zeus on a little bit of pellets, the next is a few weeks after removing the pellets. You can see how much better they look. The last pic is what Toby's poop normally looks like.