Ok, I read people criticizing BabyWise all the time and I'm just guessing that they haven't bothered reading. Here is the essence of Baby Wise. Get your baby on a schedule. First of all, make sure that they eat a full meal each time. Don't let them go more than three hours without eating at this age. Therefore, if your baby is sleeping, and it's meal time, wake him up and feed him. This is difficult to do, because you want to just let them sleep, but this does work--it gets them on a schedule. This book does not advocate letting your child go hungry. It says to feed them when they are hungry, but do NOT let them go more than 3 hours at first without eating. This will make sure they get plenty during the day, and help them sleep longer at night. It does suggest a cry it out method, but I never really did this. I comforted mine in their cribs while they were fussing. When they're screaming, you can be pretty sure they're not going to sleep any time soon. Just put him in the crib when he's tired but not asleep, and if he fusses, love on him, pat his back hum or shush him til he goes to sleep (I keep saying him, you didn't say what you have). If he's waking up hungry, feed him, it might be a growth spurt. If he just wants comfort, comfort him, but don't take him out of the crib unless he's screaming. If he is, take him out, calm him down, and put him back in before he goes to sleep again. This lets him know that the crib is where he sleeps. At five months, he should be able to sleep through the night if he's getting plenty during the day. But I remember at least one of mine did go through a growth spurt during that time. Still, this should last only a few days at the most. Oh, and I've used this book with all three of mine...very healthy kids and 3 month old now, and always a very healthy milk supply. The AAP is money led...they don't like the book because it sells so many copies and a doctor didn't write it, someone with common sense did. Several of my friends have used it, and some even used the cry it out method...I just can't do that...but they all have healthy kids!
Good luck, anad even if you don't have a ton of time, I'd read the book for yourself. Get the whole idea and then follow what you want to. Don't fall for the scare tactics of others. I wish you the best, including some peaceful nights sleep soon!!
Oh, and also, Baby Wise says eat, wake time and sleep, that way the baby doesn't rely on bottle/breast to go to sleep. On the back to sleep. It's the safest. And in the crib. Much, much safer, and also much better for baby and you.