More accurate to say, I have something wrong with my stomach.
It would be more accurate to say that I have something wrong with my stonach than I have a stomach ache.
It's more like having something wrong with my stomach than a stomach ache.
訂正する言い方は様々ですが、ここではもっと詳しく言うとという表現を使ってみました。
More accurate to say, I have something wrong with my stomach.
頭に独立構文的な使い方で、もっと正確に言うとお腹に違和感があるんです。
It would be more accurate to say that I have something wrong with my stonach than I have a stomach ache.
長い文ですが、胃痛というより違和感があるって言ったほうがもっと正確ですかね。
It's more like having something wrong with my stomach than a stomach ache.
more likeという形で、上の文を簡潔に表現しました。