Skin/Bubble covering spot where bunny should pee?

[HD12]

I have a 5 week old litter of holland lops and one is smaller than the rest and has skin/bubble covering where it should pee? (See picture) Ive never seen this before. I assume its peeing somehow since its still alive after 5 weeks. Any help is appreciated, i dont want to lose it! It also seems to have poo stuck to its bottom alot that i have to keep cleaning off. The other littermates do NOT have that problem. Thanks

 

[Preitler]

Could be some deformity, like split *****, just something else. Or is it a doe, and there's that lump on one side? Can't tell much from the very small picture or video, it's not easy to see much details at that age on pictures in any case...

Since it looks rather clean it seems that peeing works, not much to do than to see if it grows out I guess.