Can laying down to much cause you to feel dizzy light headed when u get up n walk around. doing a lot of bed rest. c diff?

Yes: Prolonged inactivity can lead to deconditioning and reduced sympathetic tone so that blood that pools in the large veins of legs and pelvis isn't squeezed rapidly into the circulatory system when standing up so that the blood pressure drops causing lightheadedness. Blood pressure meds a major cause, also dehydration. C diff causes diarrhea.