Hmmmm. What substrate do you have him on? I'm wondering if maybe he swolled some substrate or something and that has gotten impacted and is causing swelling. Probably time for a trip to the vet.
I agree with Joe, it should be broken down, or regurged if they're not digesting it.
I was planning a trip the the vet, but it resolved itself! I am keeping a close eye on the little girl though. Thanks all for the help.