After only 3 Keytruda treatments, I started having uncontrollable diarrhea, often in my sleep with no warning. I decided then I would not be continuing with treatments. My oncologist started me on a 6 week course of Prednisone. It got better, but once I finished, the diarrhea came right back. My oncologist then put me on a higher dose of Prednisone, starting at 80 mg, for 8 weeks, and after 20 lb weight gain and severe fatigue, the diarrhea has returned. Other side effects of Keytruda include hand cramps that extend up the arm, and skin rashes. I try to eat a bland diet but doesn't seem to help. Now I don't know what to do to help myself. Also I was put on a thyroid pill, another result of Keytruda.