Castor oil use for constipation/impaction

So I've been very constipated for the past few weeks and have gotten some crap out but not consistently. I think I have an impacted stool because laxatives aren't fixing the problem for long anymore. I tried an enema but I'm pretty sure I did it wrong because I got up too fast and the saline never had a chance to stay inside me to work. I have no pain at all or any serious bloating but it's just not coming out.I want to take some Castor oil because I hear that it will completely clear out any impacted bowels when a laxative won't do the trick. I've heard that as long as you take the proper dosage it should be totally safe and get it all out in a few hours.I was just wondering a few things though; how much should I take? How long should I not eat prior (I hear it should be taken on an empty stomach)? When can I eat after? Will it actually help me with this? Can I mix it with OJ? You don't need to talk to a doctor first, right?I want to bottom soon but I want this shit out of me before I do so!