My Husband Has A Creatinine Of 1.92 (chronic) And A

My husband has a creatinine of 1.92 (chronic) and a K+ now of 5.8, with normal 5.5, upper limit. He is asymptomatic. What is best laxative I can use from OTC to help get the K back to normal. ???Sennosides (Senokot OK??). Can't find a contraindication for it on internet, but did find a contraindication to KCl for Bisacodyl (Ducolax) although I could find nothing on the box about K salts in the Ducolax.