yes you should be concerned. this common behavior is called stool-holding as she desperately tries not to have a bowel movement for whatever reason (inconvenience pain on defecation memory of past discomfort on defecation etc. ) see her pediatrician so she can be properly examined to make sure there are no medical reasons for this behavior. there are stool softeners and behavior techniques that can be started to help her through this challenging time. my 4 year old grand daughter went through the same thing. the proper term is encopresis. it hurts for the child to pass the stool so they hold it in causing it to hurt more when the finally do go so next time they hold it even longer and it becomes more painful. it's an endless cycle. they will also start to have accidents in their clothes. our doctor put her on polyethylene glycol. she takes one teaspoon in the morning every day. it works wonders. she will grow out of it but for the time being this has worked wonders.
my 2 year old daughter has been refusing to have a bowel movement for the past few days. she's not constipated. she appears to be straining to poop but is in fact holding back her bowel movement. she will complain that she has pooped but it's just enough to have to wipe away. she's been on a diet of apples watermelon and peaches along with water and apple juice for past 2 days. she refuses to drink prune juice. she also is in quite a bit of pain when she "poops". her stomach is not hard and she has a fair appetite. should i be concerned?