Magnesium citrate
"I suffer from ibs-c & a sluggish colon. I have had periods of time where I could not go for 4 weeks. I tried miralax, metamucil, benefiber, rx colonoscopy preps, stool softeners, etc. I could not find any regularity. Recently, I thought I had regulated after changing meds(I was going 2-3 times per day almost every day), but after a CT scan for another GI ailment it showed I was constipated in two areas. I tried the cherry mixed w/juice warm & it made me nauseated could not finish full dose  It took about 12 hrs to work, but needed To do again. I refrigerated the lemon flavor mixed with cold juice & was less nauseated. Took 5 hrs. Need time to allow to finish, wipes a&d."