If possible take the Epsom Salts and if you want to cut down on it take it at least once at 8 pm, it helps the flush and it relaxes the ducts.. And one in the morning. Most people are fine by lunchtime.
Since you have been taking the oxy your colon will be pretty clean beforehand. I often take oxy the 3 days before. I like the buttpee so you can see things floating in the toilet, you don't want solids.