Husband quit lexapro suddenly. Off for two weeks - now taking it again - what should we expect?

You should never just suddenly stop taking medications that doctors prescribe without asking 1st as some meds stopped could cause seizures, etc. Being that has already been done but he is back on the medication, it will take time to rebuild it in his system and could take 2 or more weeks to notice it again and the benefits.
There must have been a reason why he quit taking it to begin with. If he is having any issues/problems with this medication, he needs to see the doctor as soon as possible with a list of questions/concerns.
Best wishes

I started lexapro a year ago, with mixed results, and have been an off and on user for a few months. I find that, while I'm taking the drug, I feel numb and glazed over, and have a hard time making emotional connections (I haven't been able to cry for 11 months, and have been in and out of relationships). After stopping, I haven't been able to handle withdrawal symptoms for more than a week. It usually takes between one and four weeks of regular dosage to get back to normal.
If your husband ever felt the need to quit, then quitting is the right thing to do. He should slowly taper off the dosage, with a doctor's advice. Once he's off, give it about two months, then decide whether to try another SSRI or SNRI.