Does anyone know what disease my bunny had

Hi there, I had 2 mini lops, sisters, one of which has just died. I was wondering if any one could help, they are about 8 months old. The one that died started to get slow, lie around and was a little lethargic. She was still eating fine, then she started to lose weight rapidly and got slight diarrhea, she was black and white and her white went yellow and eventually she died.

Any one know what this could have been? the other rabbit is fine and is due to have babies tonight. Thanks.

****Karen Sez****
Hard to say...Mucoid enteritis - a blockage of the intestines - explains most everything. So does enterotoxemia, although this last usually comes on suddenly and fatally.

Another possibility is some sort of genetic metabolic disorder. This would be impossible to diagnose through cyberspace. Would have been advantageous to get a vet's opinion while the animal was still alive.