Akkadian

elibbuḫu - bladder (of a bird, sheep or fish) (CAD e 89, AHw 203)

Variants: libbuḫu, ilibbuḫu, ellambuḫu, ilbuḫu, illabuḫu, ellabuḫu. Von Soden suggests that this is a Sum. loanword (see a detailed discussions in [Lieberman 222]). Part of the forms with prefixed ˀi-­ (< *ˀa- influenced by ­-i-­ of the second syllable implying *ˀa-libbuḫ- ­?). 

PS
*li/abbuḫ-, *labīḫ-at- - bladder (of animals) (SED I No. 175 )

Scarce but reliable attestation: only Akk. and Arb.