My son had the same problem, there wasn't much I could do about it. They said I could try using a thermometer and vasoline to help "lube" him up, but that was it. Your baby is still getting used to eating and using her system, it's hard to watch, my son would turn bright red and grunt and cry when he had to poop for a few weeks and eventually he got better. My nana recommended trying a little bit of sugar water, which I did, it didn't give him diarrhea but it did make him poop soon after. If you want to try it give her about an ounce of water with a little bit of sugar in it, not a lot, I'd say about 1/4 teaspoon.
I'd ask your pediatrician about what [safe] steps you can take to help little one feel better!
Also, when my daughter would get constipated I would put a little Karo Light Corn Syrup in her formula because after I weaned her from BF she was constipated ALL the time for a month or two.
You don't really hear about using that these days because they got all these meds for constipation now... but it's a less invasive way to treat constipation in younger children and babies.
I would suggest calling and asking your ped first before giving it to her though because I dunno if it's okay to give a baby THAT young some of that. I really dunno.
I'm sure it'll be okay but I'd rather be safe than sorry.
And if you say her poo's are loose, then it doesn't sound to me like she's constipated.
It sounds to me like she's got alot of gas and it's hurting her.
Kinda like when you have diarhea and it hurts while you're going because all of the bubble of gas. But it's usually fine once you're finished.
That's what I imagine is going on, and if that is the case I would advise NOT to give her any Karo because it'll make it WORSE.
Just try the infant gas drops for now and see if it improves any.
I would bring it up with her ped.
Try infant gas drops to help with the gas pain. It worked wonders when my lil one got gassy.
Is she breast or bottlefed?
Bottlefed babies are natorious [[sp?]] for being extra gassy and constipated.