I have constipation after hysterectomy 45 days ago. If double doses of miralax or laxatives work for bowels could I still have a partial obstruction.

Unlikely. It is very unlikely to have Partial Intestinal Obstruction after Hysterectomy.And also you are moving your bowels.You can slowly cut down the dose of your laxatives and try to move your bowels on your own.But if you still need the laxatives daily consult your doctor.You also need to drink plenty fluids and fiber in your diet.