I’m not saying constipation, per se, is a “serious” side effect, but here is a link to my post on the Emgality topic/thread (help James on site terminology):
Also, I was quite interested to read about the lower back pain @GetBetter since my pain management doctor is preparing to do more nerve blocks as my lower back pain has suddenly seemed to increase. I never thought of the Emgality, but the time frame fits.