Aside from the standard dietary recommendations that I'm sure you are aware of (drinking lots of fluids, raw fruits etc.), the old fashioned cleansing enema is probably the most effective home means to relieve constipation in a timely manner.
As someone who has endured the consequences of a lazy bowel as long as I can remember, and who has tried virtually every colon cleansing option available, the enema bag still offers the most economic, natural, and sure method for achieving immediate results.