Absolutely control her diet, usually that's where the problem lies. Laxitives only under a pediatritions advice. Does she eat a lot of cheese, whole milk, processed foods, high fat content? These are just the places to start and eliminate them from her diet. Encourage fresh fruits, veggies. Limit juice to no more than 4 oz per DAY, encourage lots of water instead. Use 2% (or less) milk and offer that only at meal time. Otherwise offer water to drink. Encourage her nutrition from her healthy foods rather than milk and juice. When offering juice, use only 100% juices, not the sugar water flavored by juice(Kool-Aid, 10%juices). If she starts "withholding" her bowel movements because it hurts it could lead to other issues. If you encourage more fresh fruit and veggies along with fiber and get her to drink water you will find her bowel movements more frequent(maybe daily vs weekly), softer and easier to pass. If you keep the 'bum' happy, the rest of the body will be happy too! Another help is to encourage her to listen to her body...is she really done with the bowel movement or does she just want to run off to play? Patience is key factor. If she doesn't allow herself to finish it will be more difficult next time. And beleive it or not, getting enough sleep also plays a part.