answer:Some anesthetics can cause the mucous membranes to stop producing and, mucous being the primary lubrication of the intestines, this could cause constipation. Opiates cause this in humans. Your cat may simply need some kind of cat laxative. Hopefully there is a natural herb cats take for this, rather than some strong chemical. If the cat was given antibiotics, this could kill off the natural flora in its intestines, and this could also cause constipation. Natural,unhomogenized yogurt replaces that flora in humans. You might let your cat lap a little up. It won’t hurt the cat if you’re wrong. Then again it might just be a bolus of hairball coincidentally blocking the intestine and this is easily solved within a couple of hours after giving the cat hairball medicine found over the counter in most drug or pet stores.