We were about three days into a long driving trip when I looked at my toddler daughter one evening, then at my husband. "When's the last time you changed a poopy diaper on her?" I asked him.

We were about three days into a long driving trip when I looked at my toddler daughter one evening, then at my husband. "When's the last time you changed a poopy diaper on her?" I asked him. He couldn't remember anything stinky since we had left home and neither could I. And there we had it: a constipated kid. It's not an unusual occurrence when families travel, especially by car. Explained Dr. William Cotton, the medical director of Nationwide Children's Hospital's Primary Care Network, changes in the normal routine are the primary culprit. "Constipation may occur during travel for several reasons," Cotton said. "Change in schedule, diet, the amount of liquids ingested and location." If a child is also in the toilet-training phase, that can compound matters, Cotton said, because the schedule you may have been sticking to at home gets disrupted, plus the unfamiliarity of different toilets can make a child balk at using them. If your goal is to avoid constipation in the first place, then try to eat, sleep and use the bathroom as close to the home schedule as possible, Cotton said, adding that consuming plenty of fluids, preferably water, is also key. And don't let a child sit too long without getting out of the car seat and moving every couple of hours. "Try to keep your child on their schedule," said Cotton. "Eat at the usual times, sleep at the usual times. Try to stay on the usual, regular, familiar diet." But if it happens (or if you-know-what doesn't happen, as the case may be), know that you have options. In addition to upping the fluid intake, we did (with our doctor's blessing) resort to using a tiny dose of a natural vegetable laxative on our daughter. It worked (I'll spare you the details of how well). Cotton also advocates the use of fruit juices from apples, prunes and pears. "Citrus juice won't work for this," Cotton cautioned because it doesn't contain "the kind of sugar - sorbitol - that softens stools." And finally, said Cotton, know that it's OK to trust your own instincts on how to handle the problem. "Most parents have had to deal with mild constipation," Cotton said, "and know what works best for their child."