Elaina, If you’re still having problems getting her to take water but she’s taking the pumpkin okay, try adding the pumpkin to the water and keep the syringe between her cheek and gums. You could also draw water into the syringe and then draw in a small bit of pumpkin. While she’s still lapping from the pumpkin, she’ll naturally continue lapping as the water goes into her mouth. And you could also dilute the formula. To make sure she’s still getting the same amount of formula/nutrition each day, just give it to her more often.
I do like snow kitten’s suggestion for soaking her bottom to help ease the constipation – it’s also a good way to get her used to water for future bathing.
One more note: Pumpkin is also used to help with diarrhea. Fiber binds but it also helps move things along. If she’s not getting any relief from the pumpkin or the “bath” you might consider mashing a small blueberry, make sure it’s not straight out of the fridge, and adding it to some water for the syringe. Start with the smallest amount and give it time. You don’t want to start an avalanche.