Bowel movement during clear liquid stage?

My husband had surgery on Monday 5/23. He came home from hospital on Wed 5/25.
He has been on a clear liquid diet since two days before surgery.
Even though he has taken Milk of Mag for the last two days he still hasnt had a bowel movement?

Should he still be haing bowel movements if he has had only clear liquids for last  8 days??

 I didn't have a BM for 7 days after my RNY and then it was another 10 days before my next BM. Constipation is a problem. My doctor said to use 100 mg Colace and Benefiber to keep things moving. I love the Benefiber Cherry Pomegranate. They come in stick packs you add to a bottle of water.

Lose the Milk of Mag!!!  If he is on liquids only it means he has not had any bulk and is less than a week out of surgery.  He's not going to have anything to poop.  It is not uncommon to NOT pinch a loaf for up to a week after surgery.  If he goes that long then I'd be worried otherwise patience Grasshopper.

I had surgery the very same day and I have not had a BM yet eiher, and asked the very same question, everyone just says patience