In cases of severe constipation is it ok to take miralax (polyethylene glycol) twice a day?

More or less: Yes, MiraLAX (polyethylene glycol) or peg 3350 is a safe way to introduce more water and therefore all the benefits of a stool softener into your daily routine. Most laxatives can cause painful cramps and ultimately are habit forming. If a water stool develops return to one capful daily. Remember to introduce more exercise and make time for your daily routine.