His guts clenched with fear, but he fought the temptation to tell her.

His guts clenched painfully at the thought of their losses.

His gut clenched, and he forced his eyes up to her face.

Her tongue swept out, and his gut clenched in reaction.

When they returned a few moments later, his gut clenched.

As she knelt in front of a toilet, her gut clenched.

His gut clenched as he forced himself to say the words.

He already knew what the sound was, and his gut clenched.

"That's where I was," she whispered, and my gut clenched at the sound of realization in her voice.

My gut clenched at the lost sound of his voice.