What Causes Clear Mucus Discharge In Stool And Abdominal Pain While Having Adenoidectomy?

My 5yr old had an adnoidectomy, tonsilectomy, & nasal cauterization 36hrs ago. He is taking tylenol with codiene q4 hrs and magic mouth wash for pain t.i.d. Today he started having bowel movements (incontinent at times) that are purely clear mucus containing no fecal matter. He has not had a "real" bowel movement since before his surgery. He is not complaining of abdominal pain.