I Had A Colonoscopy Aug. 4. My Energy Level Has

I had a colonoscopy Aug. 4. My energy level has been low since. I have been eating 3 meals a day with proteins, and fruits and vegetables, as I normally have. My appetite is not the same - I'm eating less. I'm trying to drink lots of water, because I know you get dehydrated during the prep before the colonoscopy. Today I have stomach cramps, and diarrhea, the most recent was dark brown and watery. Could I be dehydrated?
Thank you for your time. Cheryl