Listening to your child cry is heart-wrenching. No parent enjoys it. Sixty seconds of crying can seem more like sixty minutes. The reason a parent chooses to go the route of cry it out (CIO) is because the result is a baby who sleeps well, and sleep is vital for proper brain development. When Brayden, my oldest, was first born, I was not sure I wanted to do CIO. I was perfectly willing to help him fall asleep by rocking him. We went that route until he was 9 weeks old.
Here was the problem with rocking for Brayden. The entire time I rocked him, he cried. It would take about 40 minutes of rocking and he cried the whole time. Then he slept only 30-60 minutes. I could tell he was tired at all times, and in the end I decided I could either hold him while he cried it out, or he could be in his bed when he cried it out. Me rocking him was not soothing for him or me and it wasn't helping him sleep well.
An interesting thing happened when we started CIO at 9 weeks old. He cried for less time in his crib. His naps were still the same length, but the crying was less. One day after starting CIO, his nights went down to one waking a night instead of several. He was learning to sleep on his own and sleeping better overall.
After our positive experience with Brayden learning to sleep on his own, I was a believer in the CIO process. But that didn't mean I liked it any more. Nope. Still hated it. I would compare it to exercising. Hate it. It can suck. But it works. The difference between the two, however, is that CIO doesn't get easier with time.
By the time my third child was born, I read about the 4 S's from the Baby Whisperer. This was a life changer for us! Following this with my third and fourth led to rare crying ever from birth on. I can't recommend this method for you enough. You get the independent sleeper without the crying. Win-win.
CIO and Babywise
Let's get one thing straight. For some reason, there is an idea that to do Babywise means you must do some form of hardcore CIO. It just isn't the case. The book mentions that your baby might cry when learning to fall asleep. It also encourages you to avoid sleep props. But there is no guide to sleep training. The book recommends you make sure baby can fall asleep alone. The reason for this is that babies, just like adults, wake up multiple times a night. Babies wake up in the middle of nap (45-60 minute mark). If a baby cannot fall asleep alone, then baby will wake up fully and need your help to fall back asleep.
So your goal with sleep is just that baby can fall asleep alone so that mid-nap and mid-night baby can go back to sleep without help. You do not have to do CIO if you do not want to. For more on sleep training and Babywise, see Sleep Training According to Babywise. Again, I personally highly recommend using the 4 S's from the Baby Whisperer as the preferred method of sleep training.
What Age Can You CIO
Back to the topic at hand, cry it out. People who have decided to CIO often have the question, "What age am I okay to start CIO with my baby?" There is so much conflicting information out there on this topic. You have everything from "birth" to "never." Most people who agree CIO is okay agree that around 16 weeks of age is okay to start. Most will also say between that 16 weeks and 6 months old is your sweet spot time when you will have the least amount of crying overall and the fastest success rate. This means fewer days of crying.
My personal thoughts are to trust your "gut." I give a lot of weight to mother's intuition. If you feel your baby is ready for it, give it a try. Do not start, then stop, then start, then stop repeatedly. If you start and decide, "I was wrong!" go ahead and stop and try again at a later date, just not the very next nap. Don't start it until you are confident baby is ready and that you are ready. Otherwise all you are doing is making baby cry for a period of time for no reason.
Some people worry they are too late for CIO to work. There really isn't an age that is "too late." The older the baby/child, the less there will be "crying" and the more there will be calling out, "Mommy!" But it can still work.
Before You Start
Before you start with CIO, be sure you have thought it through. Be sure you feel good about it. Be
sure you have read the information I have for you below so you go into it mentally prepared.
I would also advise you do your best to limit sleep props up until the day you start CIO (and after of course). If your baby has sleep props, then you are having crying to wean from the prop and to learn to sleep. Double whammy. Do you best to keep those sleep props to a minimum.
Find a good support group. There are many good Babywise groups online that can be your support through it and troubleshoot things with you. The Chronicles Google Group is fantastic. There are helpful and supportive groups on Facebook. There are many groups out there, so find the one that works for you and use that support network. "In my day" (seriously people, I am old enough for that statement), those support groups weren't available yet. Best of luck to you!