kidney and magnesium

Hi- i need daily magnesium to stay regular. its the only thing that helps. i was taking Mg citrate for 6 years and recently switched to Mg Chloride and alternatie with Mg hydroxide. before i started taking Mg supplements my serum creatinine was always borderline elevated. its still the same but i feel i may have some renal issues. is it safe to continue magnesium? if i stop i will get horrible constipation..i cant tolerate any fiber and stool softeners give me bad spasms. please help thanks Tweet