Ruud bothered by stomach ache against Zverev?

Casper Ruud asked the tournament doctor to intervene on court at the start of the 3rd set of the second French Open men's semi-final against Alexander Zverev. He seemed to describe that he was suffering from a stomach ache and took a pill that should help him remedy it.

At any rate, this could explain the Norwegian's slump since the middle of the 2nd set. This information should be taken with all due caution, of course, and confirmed between now and the end of the match.