'Stomach' in the Bible

(Resh) Look, O Lord! I am distressed; my stomach is in knots! My heart is pounding inside me. Yes, I was terribly rebellious! Out in the street the sword bereaves a mother of her children; Inside the house death is present.

(Kaf) My eyes are worn out from weeping; my stomach is in knots. My heart is poured out on the ground due to the destruction of my helpless people; children and infants faint in the town squares.