"urge but cannot pass stool"

Feeling the Urge but Unable to Pass Stool: Do Not Force It with Functional Constipation

Why does sitting on the toilet feel so frustrating? Have you ever broken into a cold sweat because you clearly felt the urge to defecate, yet nothing came out smoothly no matter how hard you pushed? Straining until your face turns red and your anus aches, only to be left with lingering discomfort, is an experience I understand all too well.