I'm running through my list of suggested topics from readers, and this one goes out to Parv from Sheridan, IN. I tried to save constipation for last since it's one of those topics that doesn't usually come up in casual conversation.

There are three common times in a person's life when constipation can become a problem. The first is during the early childhood, the second when a person has decreased activity for some reason, and the last is during the elder years. Each of these is characterized by different causes.

First, I have to deliver yet another lesson in basic anatomy and physiology. When we eat, food travels through the following structures: mouth, esophagus, stomach, small intestine and large intestine. This journey is facilitated by peristalsis, a process where involuntary muscles along the digestive tract contract and move what we've eaten from north to south.

While constipation can involve trouble anywhere along the way, the vast majority of problems occur in the colon. One of the main jobs of the colon is to reclaim water from the stool. If the stool is slowed down in its transit, more water is absorbed, making the stool firmer.

Young children can develop problems with constipation when they put off going to the bathroom for various reasons. When this happens, they can retain incredible amounts of stool in their colons. This stretches the wall of the colon and weakens the muscles responsible for peristalsis.

Eventually the colon dilates to the point where the muscles are not able to push the stool out and the child may lose the urge to have a bowel movement. These children may pass very large bowel movements and may have a great deal of pain when doing so. This pain leads to the child not wanting to have a BM and the cycle repeats itself.

Another common cause of constipation is a period of inactivity, especially after surgery. This is especially true following abdominal surgery, particularly if it involved manipulating the intestines. When a surgeon handles the intestines it tends to interrupt normal peristalsis for a period of time. Taking pain medication post operatively can cause things to slow down even more.

Older persons are also more likely to be inactive so they tend to suffer from bouts of constipation. Often these folks are on medications that can exacerbate the normal age-related slowing of intestinal motility. Some of the common drugs that can cause this slowing include Benadryl®, Tylenol PM®, Zantac®, some antidepressants, and medications used to treat bladder spasms and incontinence.

As usual, prevention is the best medicine. All people should consume adequate fiber as well as fruits and vegetables. Children need to be taught the habit of sitting on the toilet at least twice a day for 10 minutes or so. They should not be rushed and should have good support for their feet.

Those who are having surgery or who are laid up for another reason should make sure they are consuming plenty of liquids and they should take a stool softener like docusate or Miralax® on a regular basis starting at the beginning of their illness, before constipation becomes an issue. The elderly should consume fluids and also get as much exercise as possible. We joke a lot about prunes, but they really do work.

Young children who have difficulty with bowel movements should be evaluated by their physician. The earlier this problem is treated, the easier it is to correct. For adults who are suffering from constipation who do not have abdominal pain, laxatives such as Dulcolax® are generally safe and effective for short-term use. If results are not obtained in a few days, you should contact your doctor.

Dr. John Roberts is a Crawfordsville physician and one of the owners of The Paper. IN addition to his weekly column, he writes a daily health tip that can be found on page A1.