It's a sad day when poop just isn't funny anymore ... at least for someone like me who does enjoy poop humor and things scatological (it's an occupational hazard). That sad day is a lot more likely to happen when travelling to adopt a child. In fact, constipation is so common a concern for travelling adoptive parents that I've taken to inventing medical terminology with a reassuring cachet such as "transitional slowed bowels", just to take the edge off of the hour-and-minute countdown since last passed stool. It's also a problem for many other children in my practice ... our modern processed diet may be to blame, as a diet low in fiber, low in fluids, and high in sugars predisposes kids to constipation.

In general, constipation is defined more by what your child is passing rather than how often. Normal stool frequency in infants varies from several times a day to 1-2 times per week. But if your child is passing painful, hard "rocks", "golf balls", or "boulders" (egad), especially if there is intermittent leakage of more liquid stool (encopresis), then indeed we've got a problem. If your child is vomiting, or has a full, tight, and tender belly, then we've really got a problem needing urgent medical attention.

In the recently adopted child, constipation is often blamed on iron, when in fact it's more likely to be from the stress of travel and transition, dietary changes, and perhaps dehydration. The association between iron and constipation is overrated, and since most adoptees are iron-deficient, it's not wise to try and limit their iron intake.

Soy formula can cause harder stools, so you may not want to switch your child to this if constipation is an issue. Luckily, cow milk intolerance is another overrated issue - most infants and young toddlers tolerate cow milk products just fine (rarely, cow milk protein allergy can be associated with intractable constipation).

To assist you in your quest for smooth bowel movements, or Smoovements^TM, if you will ... I will now share with you ancient secrets of "FPBM - For Proper Bowel Movements". Let's start with F - FLUIDS, FRUITS, and FIBER are your Friends when it comes to constipation.

Infants:

several ounces of 100% fruit juice 1-2x/day, especially prune, pear, or apple juice
fewer white foods like bananas, rice, soy, cheese, white flour products, and ...
more "P" fruits and veggies like pears, peaches, prunes, plums and peas
substitute barley cereal for rice cereal
in hot climates where dehydration is a concern, a few extra ounces of water can help, but since our kids usually need the calories, I'd stick with juice or watered-down juice
if you've gone more than 3-4 days with no stool, and your child seems to be in pain or straining a lot, try a glycerin suppository and a warm bath; you can also gently lubricate around the anus with vaseline or diaper cream
if your child is straining, you might try bicycling their legs or holding them upright in squatting position (their back against your chest, holding their knees up towards their chest)

Toddlers and Older Children:

fruit juice, and fewer white foods/more "P" fruits and veggies as above can help ...
... but in this age group, we should focus more on fiber and fluids: goal is at least their age in years plus 5-10 grams of dietary fiber per day, with lots of fluids
whole grain cereals (read the label - lots of fake "whole grain" stuff out there) - remember "Colon Blow Cereal" from Saturday Night Live? That's the ticket - bran cereals, whole grain cereals, muesli, mini-wheats, etc ...
bran muffins, cookies, crackers, and pancakes with whole grains. Metamucil makes some psyllium fiber cookie-type wafers as well ...
Benefiber is a nongritty, flavorless fiber supplement that dissolves more completely than Metamucil, for when you can't meet the fiber goal through diet alone
You can also get your 100% juice plus 10g fiber premixed in one convenient but pricey juice box (they also carry fiber cookies)
dried fruits (prunes, apricots, figs, raisins, etc)
beans, peas, and lentils
fresh fruits and veggies with fiber - carrots, cabbage, celery, rhubarb, prunes, pears, peaches, plums, apricots
the constipation chapter below has nice recipes for "Right and Regular" jam and fruit/fiber smoothies
you can try 1/2 tsp unprocessed bran or flax seed mixed with food 1-2x/day but only if your child is drinking adequate fluids
for kids 4yo and up, popcorn is a great, tasty source of fiber, as are seeds and nuts

"B"-havior:

in older children with constipation, suggesting regular sitting sessions 2x/day can help - after meals is the best time
reward successes, lay off the failures (it's bad enough as it is)
regular exercise keeps you regular
for kids who are fearful of pooping from passing painful large-caliber stools, sitting backwards on the toilet leaning onto the tank can help
3-5yo "magical thinkers" often feel that if they withhold stools after they've had a painful experience the poop will disappear. It won't. It'll just add to their "boulder collection". Reinforce that the poop needs to come out every day, and help it do so with diet, regular sitting, and Miralax.
counseling may be necessary (and very helpful) for older children with encopresis

Medications that start with M:

if diet isn't working, if symptoms are severe, if your child is withholding stool, or if there's leakage (encopresis) you need to talk to your doc
my hands-down favorite laxative is Miralax, a tasteless powder mixed into your choice of fluids that is very safe, well-tolerated, and effective ... and now available over-the-counter
if you've been dealing with long-standing constipation or encopresis, you need to continue interventions like Miralax for 2-3 months at least, to help the rectum and colon recover to a normal caliber
Maltsupex or Milk of Magnesia are also frequently used
Mineral oil is another old favorite but it's yucky (try it in ice cream) and can pose an aspiration risk in younger children
bowel stimulant products like senna can be used occasionally but are not for chronic use
DON'T enemize your child without consulting a physician, and avoid frequent rectal interventions in general (unnecessary and traumatizing)
DON'T give honey or karo syrup to infants - there have been cases of botulism from this. UPDATE: Karo syrup manufacturing processes are now considered safer, but karo syrup no lomnger contains some of the helpful glycoproteins, so it may be less effective.