Papaya along with Pineapple contains enzymes (bromelain and papain) that help break down particles of food and mucous (proteins, fats and sugars) that bind together fur in the digestive tract (hairballs) in the rabbits stomach. Pineapple, specially the stem contains Bromelain, one of nature’s most powerful anti-inflammatory. This helps to prevent clogging in the intestines and it is also great for joint pains, fever and inflammation. Pineapple not only contains bromelain, it also contains vitamins B & C, sterol, Omega 3 & 6; all these substances work together in synergy. These enzymes and vitamins can be useful during molting season to reduce the development of fur related blockages.
You might not always have papaya or pineapple handy, what you can do is freeze some papaya and or pineapple with the skin in a Ziploc bag. When you notice that your rabbit might not be eating as it should, thaw out one of the baggies and peel off the skin and mash up the fruit in the same Ziploc bag, you instantly get baby food consistency that can be syringe fed to your bun.