Three Days Ago I Developed A Heavy Feeling In My

Three days ago I developed a heavy feeling in my lower abdomen with lots of cramps. I have had a problem with constipation in the past so I took mirolax at bedtime. The morning brought results. However, I still have a painful and tender to the touch lower abdomen. I also have developed tenderness and pain in my low back area. The tenderness almost completely covers from my waistline down. The pain is an ache. No burning with urination. What should I do for relief?