Gallstones
noun
Stones that form in your guts are gallstones. Sometimes you have to get them surgically taken out. Scary!
たんせき
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
胆嚢炎は、ほとんどの場合、胆石が原因です。
With inflammation of the gallbladder, the most likely cause is gallstones.