Since 24 hrs diarriah yellowish did colonoscopy 3 days ago. All good, not eating well going to bathroom almost every hour. Please help?

It will pass. Drink plenty of fluid especially with sugar and salt. If its small amounts, even if frequent, and you're not dizzy when you sit or stand up, you should be fine. If large volumes or you get dizzy upright, you may need intravenous fluids. Have some salty broth a couple of times.