hi K.,
this started happening with my daughter too around the same age, we had recently introduced her to the idea of a "potty",nothing more than putting one in the bathroom explaining what it was for and asking her if she'd like to try, which she did on occasion want to try and did. For a couple of months she was very content to use it sometimes and others disregard it, then everything changed. It was after dealing with two months of almost daily tears and "i have to poopy!" screams, paired with running around the house in an effort it looked like, trying to run away from the pain, would lead to a very painful "poopy" only every 4-5 days or so and required at least 20 min of me holding her, soothing her and talking her through it, that i finally took her to the pediatrician. apparently it is very common among girls, once they realize they have control and are aware of the sensation, they will hold it causing a back up if this happens time and time again the bowel will stretch and the muscles they are now just beginning to use, will be trained improperly, and as it was in my daughters case, cause severe impaction.
Her pediatrician prescribed (don't worry it's over the counter) MiraLax with the instruction to try 1 teaspoon first, every morning and evening, working my way up to no more than 3 teaspoons every morning and evening until we find a what brings daily relief (may take three days to two weeks to find right dosage)once your daughter is able to comfortably produce "peanut butter like texture" bowel movements every 1-2 days continue three months of this dosage before you taper dosage, slowly and over time removing it completely. do not try and potty train during this time. abandon your part in "The potty" completely, but if she so chooses to make of it's use, comply and offer praise. The pediatrician explained her bowel needs time to heal, shrinking down to it's original size and the smooth muscle use should be allowed to retrain naturally without interference. Has worked wonders with our daughter who is now 34 months old and completely potty trained day and night without the use of pull-ups. I still give her 1 teaspoon of Miralax a day, but will continue to ween her from it over the next several months. While the MiraLax has allowed our daughter to heal and put an end to the immediate cause for her discomfort, more importantly we followed pediatrician's advice to maintain a high vegetable diet naturally through whole grains and high fiber fruits and veggies. I hope you are able to alleviate the pain and discomfort your child is experiencing and you have found this advice helpful whether or not you choose to follow it. in any case if what you try doesn't make it better seek the advice of your pediatrician, because there are many, many things at play here, some much more serious than an impacted bowel, which require trained medical professionals, especially if you have noticed changes in her weight, activity levels, sleeping habits or physical features, combined with her constipation.
good luck to you and your little one,
aline
* MiraLax comes in a white plastic bottle with a purple and pink label. It is an odorless, tasteless powder you simply add to her drink. (yes even in water she won't know it's there)
* You can find MiraLax at any drug store i.e., Target, Walgreen's, Longs Drugs, Rite-Aid, etc. Probably better to buy the big jug of it, 17.9 oz, which costs about $23.00, if you plan on continuing its use as it was prescribed to my daughter and explained above.
* Don't hesitate to contact me via e-mail should you have any additional questions: ____@____.com, and again good luck to you and your daughter.