Sticky bottom syndrome in rabbits is most often caused by feeding a badly balanced diet, or simply feeding too much food, resulting in over-production of caecal droppings. Rabbits will not eat the excess pellets.
Fat and elderly rabbits (especially females with large dewlaps) are also at risk as they may not be able to reach their bottoms to practice coprophagia and to clean.
Rabbits with dental disease may not eat their caecal pellets and won’t groom themselves properly either, also putting themselves at risk.
Pet rabbits can get worms (usually if fed on green food collected from areas frequented by wild rabbits), but clinical problems are said to be rare. However, some rabbit owners report sticky bottom problems clear up after the rabbit is wormed.