Hello! Thanks for putting your query in HCM. I am a Gastroenterologist (DM).
Actually for colonoscopy
you must have done bowel preparation with polyethylene glycol
etc. This may happen after colonoscopy and its preparation. I hope you this will improve in another day or so, if not then consult your treating physician
I hope I have answered your query and this will help you. Remain in touch and get-well soon.