Do you have any specific recommendations to prevent large fluctuations in sodium levels during a colonoscopy prep in patients with central diabetes insipidus on DDAVP?  

Interesting, I have just received a message from a patient in this very same situation. I am not aware of any specific literature on this. In absence of such data, I usually recommend remaining on the same desmopressin dose and obeying to thirst, as I worry about hyponatremia that may be caused by a...

I agree there are no standardized recommendations. Some literature suggests that up to 7% of normal patients can develop hyponatremia associated with colonoscopy, so extra desmopressin could indeed be problematic. In many of our patients with diabetes insipidus and completely intact thirst, we advis...

I agree with Dr. @Salvatori. Colonoscopy prep does not require any change in liquid intake so I don't expect that any change in DDAVP dose would be required.