It Was a Strange Time in My Life

"Either that or they are miserable from all the shit they've been storing."

I can never figure out what this line is supposed to mean. Are they miserable because they're bottling up a whole bunch of pain and suffering, or is it constipation? I want to believe it's the first suggestion, but ever since someone brought up the other, I can't get it out of my head and now I'm upset >.<