the pounding hearts and lurching stomachs?

[Hongdung]

Hello,
I read the sentence bellow:
"Thank Mum for getting rid of all the pounding hearts and lurching stomachs."
I'm very confused with "the pounding hearts and lurching stomachs". What does it mean? Can you help me to explain the meaning of this?
Thank you very much
Jung

[Cerberus™]

When you experience strong emotions, mainly negative ones such as fear, your heart may be said to pound and your stomach to lurch. "Mum" has presumably gotten rid of her child's fears? It depends on context; as it is, the situation described seems to be a bit unusual.