Q. I am a 42-year-old stay-at-home mum and I have suffered from constipation since my youth.

It is severe now and I usually manage to clear my bowels only after four or five days. It often gets worse when I am on vacation. It seems that no amount of food, not even fruits or fibre helps. They only make my tummy more bloated.

About a year ago, I began taking Dulcolax. But I worry that I may be overly dependant on it as I become constipated as soon as I stop taking it.

Is it bad to rely so much on laxatives? Is there any test I can take to check if my intestines, colon and rectum are functioning all right? Are there other safer or better methods I should try to solve my constipation problem?

A. There are many causes of constipation. A good history will have to be taken and a clinical examination carried out to help distinguish benign from potentially dangerous causes. Your having had constipation since your youth is of some comfort as it is less likely to be due to a serious disease such as cancer of the colon.

You are much more likely to have slow transit constipation, with slow passage of material through your bowels. A history would elucidate your bowel habits when you were young, whether you cultivated regular habits or poor bowel habits such as consistently resisting the urge to move your bowels.

A dietary history would reveal whether you have an adequate fibre intake. A drug history is important as chronic use of some medicine can cause constipation, and overuse of stimulant laxatives over many years may adversely affect bowel function in the long term.

Some basic blood screening tests will be helpful to exclude systemic diseases that are associated with constipation, such as chronic diabetes or under-functioning of the thyroid gland.

An examination of the large intestine or colon, by means of flexible endoscopy may be considered, to exclude structural problems such as large obstructing polyps, strictures or cancer. You should discuss this with your doctor.

There are also tests of colonic transit time and your defaecatory mechanism (bowel clearance capability) that can be done, but these are not routine and will only be considered if your doctor feels that they will be helpful.

It is better to use Dulcolax (Bisacodyl), a stimulant laxative, to treat severe constipation only occasionally. Its frequent use is not encouraged as it may change the ability of your bowels to function normally.

If you do indeed have slow transit constipation, the solution is often to first clear the bowels thoroughly by the once-off use of a stimulant laxative.

Then maintain a good bowel habit by the regular use of fibre and an osmotic laxative, with only an occasional stimulant laxative if constipation becomes severe (if, for example, you have not moved your bowels for more than seven days).

Soluble fibre, such as ispaghula or psyllium, is better than insoluble fibre such as bran. Osmotic laxatives include Lactulose or Polyethylene Glycol preparations titrated to achieve a satisfactory bowel habit. Dulcolax or Fleet are the stimulant laxatives of choice when really needed.

If it turns out that you have a specific defaecatory disorder, management will be more complex and may include biofeedback training or even surgery. Such disorders are much less common.

If your bowel habits remain unsatisfactory, especially after a period of self-medication, you should consult your doctor to get a proper evaluation and develop a strategy to deal with your constipation.

Dr Tan Chi Chiu

Dr Tan Chi Chiu is a gastroenterologist at Gleneagles Hospital.

This article was first published in Mind Your Body, The Straits Times.