I Have Taken Ducalax, Milk Of Magnesia, And Magnesium Citrate,

I have taken ducalax, milk of magnesia, and magnesium citrate, the latter two tonight with no results. I have been constipated for 4 days with no bowel movement. Am up all night with discomfort but no pain. I have one kidney and have had constipation off and on for about a year. Had surgery after kidney was removed because the surgeon nicked my pancreas. Barely made it. 73 now. That was five years ago, the surgery. I drink plenty of water. I am considering going to the emergency room.