Gastrointestinal disease in rabbits
A rabbit's digestive system is designed never to be empty and constantly contains food, caecal pellets and hair ingested during grooming. If a rabbit stops eating or reduces its food intake then the gastrointestinal tract will go into stasis, where it slows down or comes to a complete standstill. This in itself can prove fatal within just a matter of hours.
There are a variety of reasons why rabbits may suffer with a dirty bottom, either with faeces or urine, both of which are potential attractions for flies, especially in warmer months of the year when flystrike is a common occurrence. Rabbits naturally produce soft faecal pellets which are then reingested but if some reason they cannot reach round to clean these up eg if they are overweight or have dental problems their bottom may become matted and dirty.