Studies have shown that cats are prone to developing anal sac impactions, which occur when anal sac secretions build up due to the tube or duct of the anal sac being clogged up. (petsmagazine.com.sg)
If your cat has had anal sac impaction in the past, or regularly needs to be manually expressed, you probably already are paying close attention to potential symptoms of problems. (thesprucepets.com)
Cats that have experienced anal sac impaction and subsequently felt pain during defecation may develop an aversion to the litter box. (cathealth.com)