What Is The Treatment For Constipation And Tiredness?

Hi, iv been having this problem, where it feels like my intestine are tied in a knot....i dont know how to explane it, it happened the first time about 2 months agow, and it hurt so bad i was curled up in a ball on the bed, and thought maybe i was having a miscarriage, (thats because i just had a baby 5 months agow, three months agow at the time of the occurrence, but had still not had a peoried yet, so was getting worried that i was pregnant, and that maybe i was miscarrying) but i wasnt bleeding or anything, then finally a couple hours later i went to the bathroom and had a BM, witch hurt really bad, but finally when i was finished i felt better. and ever since then its been happning on and off...where it feels like my intestence are tied in a knot, and it hurts realllly bad to pass gas or go to the bathroom....what could this be????

thanks...!