expression, i-adjective
have an upset stomach; have loose bowels
Describes a condition where one's stomach is unsettled, often leading to soft or loose stools. A common, mildly euphemistic expression.
昨日からお腹がゆるくて、何度もトイレに行っている。
My stomach has been upset since yesterday, and I've been going to the bathroom many times.
冷たいものを飲みすぎると、お腹がゆるくなることがある。
Drinking too many cold things can sometimes make your stomach loose.
下痢 is the medical term for diarrhea, while お腹がゆるい is a softer, everyday expression for having loose stools or an upset stomach.
お腹を壊す means 'to get an upset stomach' (often from food poisoning or overeating), focusing on the cause or event, whereas お腹がゆるい describes the ongoing state of loose bowels.
A set phrase combining お腹 (stomach) with ゆるい (loose, not tight). The expression figuratively describes the looseness of bowel movements.