Hello, this is Dr. E. Greetings from New York! I'm so glad you posted your question for me to answer, and I aim to provide you with accurate info.
Keep taking the miralax and start milk of magnesia as well - your stools should start running clear. If no profuse bowel movements by tomorrow morning you may need an enema and or fecal disimpaction by a physician. This is worrisome for a partial small bowel obstruction if no improvement.