I'm constipated and think I might have hemorrhoids or an anal fissure. Can't go to the doctor for a week. Is it safe to sake Senokot or Miralax (polyethylene glycol)? Both?

You can take. either, but I would recommend Miralax (polyethylene glycol). It dissolves in 8 oz of any fluid, such as water. Until you can see the doctor, you can also apply some healing ointment, such as Aquaphor to your anal area. If it's a fissure, that may even heal it. Working on the constipation is the real factor here,so try to increase the fiber and fluids in your diet...and certainly see your doctor.
Constipation. Yes it is safe to take Miralax (polyethylene glycol) and I would take one or two capfuls a day and adjust as needed to have one or two soft stools a day.