No, it's not safe to take it for long periods of time as it has senna. I've posted tons of easy and natural alternatives that will cure constipation, have you seen the list? :)
Sometimes it just takes time (months!) for the colon to get strong, and for the liver to get de-congested enough to produce enough bile. And if you eat things that are constipating or wrong for your body type, well, then the constipation will not go away. As healthy as my colon is, if I overdo on fudge then hooo weee I suffer! :)