Larry has an upset stomach.

拉里胃不舒服。

《柯林斯英汉双解大词典》

He had an upset stomach.

他胃部不适。

《柯林斯英汉双解大词典》

"I got an upset stomach, and I did not feel rested at all," He said.

他说：“我肚子不舒服，人也根本就没好好休息过。”

youdao

My mom called a flight attendant to ask what "they" had for an upset stomach.

WSJ: Marisa Acocella Marchetto on the Flight Attendant From Hell | Traveler's Tale

All they are likely to do for a healthy person is cause an upset stomach.

CNN: What to do if you have the flu

Mrs Jones said she had been concerned about April on the day before she went missing because the little girl had complained of an upset stomach.

BBC: April Jones in the leisure centre