When facing constipation, especially extreme constipation, I do not think that it is good to force it out. The problem with constipation is usually the opposite of diarrhea. There is insufficient water in the stool to keep it soft and pliable.
My solution would be first to consume lots of water to restore the balance. Then if it did not proceed naturally, use a laxative. I personally prefer Epsom Salts because it provides additional water, and it also provides magnesium which is important for peristalsis.
If your constipation is due to a shortage of magnesium, then you are also at risk of cardiac failure.