No, not constant pain but before I started the Prunelax, and trying everything, I would go for days without elimination and then I would have heartburn, and I would swell up and not be able to hold my stomach in, like I normally do without any problem. I would feel nauseated also. I'm not sure how my colon is configured but I know that it is tortuous. I run the risk of tearing it or puncturing it during a colonoscopy. Which I have decided that because of this risk and how hard it is on me afterward, I'm not going to have any more. There are other procedures apparently that can be done that i wouldn't be at such high risk of further damage to myself.