Why more fiber isn’t always the answer.

Constipation is one of those ailments that most people think they know how to treat — the majority believe that simply eating more fiber is the answer. But this often doesn’t work.

What few people realize: Chronic constipation can have some very surprising causes… and dietary changes alone help only about one-third of those with the condition. What’s more, if overused, some of the same laxatives that relieve constipation initially can exacerbate it in the long run, so most people need additional help to really get rid of their constipation.

WHAT’S NORMAL?

Most people have one to three bowel movements daily, while others have as few as three a week. This variability is normal.

What’s more important are changes in bowel habits, particularly if you’re having fewer bowel movements than usual and also are experiencing other symptoms that could indicate a more serious problem — such as blood in stool (colon cancer)… unexplained weight loss (diabetes or colon cancer)… or weight gain (low thyroid function).

The first step: Even though not all people with constipation will improve by eating a fiber-rich diet, it’s still wise to start by eating more fruits, vegetables, legumes and whole grains that are high in fiber. In general, people who consume 20 g to 35 g of dietary fiber daily — and who exercise regularly — are less likely to suffer from constipation than those who mainly eat a meat-and-potatoes diet. Examples of fiber sources: One cup of oatmeal or a bran muffin provides 4 g to 5 g of fiber.

Helpful: Be sure to eat the vegetables and fruits that are most likely to draw water into the stool to facilitate soft, bulky bowel movements.

Best vegetables to ease constipation: Those in the Brassica family, such as broccoli, asparagus, Brussels sprouts, cauliflower and cabbage.

Best fruits to ease constipation: Peaches, pears, cherries and apples (or apple juice).

If your constipation doesn’t improve within a few weeks, then…

  1. Check your medications. Many prescription and over-the-counter medications slow intestinal movements and cause constipation. Narcotic painkillers, such as oxycodone (OxyContin) and the combination of acetaminophen and oxycodone (Percocet), are among the worst offenders. Tricyclic antidepressants, such as amitriptyline (Elavil), also can cause it. So can medications that treat high blood pressure (calcium channel blockers) and Parkinson’s disease.

    Helpful: Constipation also can be triggered by the antihistamines used in allergy medications, such as cetirizine (Zyrtec) and diphenhydramine (Benadryl), if used daily. Lowering the dose of an antihistamine drug or taking it less often may reduce constipation.

  2. Get your magnesium and potassium levels tested. Most people get sufficient amounts of both minerals in their diets. But if you take a daily diuretic or laxative or have an intolerance to gluten (a protein found in wheat, barley and rye), you may be deficient. Low magnesium or potassium decreases the strength of intestinal contractions — this may contribute to diarrhea or constipation.

    Important: If constipation doesn’t improve within a month of boosting your fiber intake, see your doctor. The problem could be due to a deficiency of either or both minerals. If a blood test shows that you have low magnesium and/or potassium, supplements can restore normal levels within a week or two (ask your doctor for the appropriate dosage).

  3. Be cautious with calcium. High-dose calcium often causes constipation, particularly in people who take antihistamines or other drugs that slow intestinal transit time (how long it takes food to pass through the bowel).

    My advice: Get most of your calcium from calcium-rich foods. If your constipation is related to high-dose calcium supplements, talk to your doctor about limiting the supplement dose to 500 mg to 1,000 mg daily — and be sure to eat plenty of high-fiber foods and drink lots of fluids.

  4. Drink at least two quarts of fluids daily — more if you exercise or engage in activities that cause you to perspire heavily. Drinking this much fluid increases lubrication and makes stools larger, which helps them pass more easily (and frequently). Water is best — it has no calories and usually is the most readily available fluid.

  5. Avoid laxatives. Some of the most popular products actually can increase constipation. So-called stimulant laxatives, such as Dulcolax and castor oil, cause the intestinal muscles to stretch and weaken with continued use. People who use these products frequently may become dependent — they can’t have a bowel movement without them.

    Important: It’s fine to use these products occasionally — when, for example, you haven’t had a bowel movement for several days and are feeling uncomfortable. But if you use them more than once or twice a week, it’s too much. Talk to your doctor about healthier methods such as those described in this article.

  6. Relax and reregulate. If you get enough fiber and drink enough fluids but still are constipated, see your doctor. You may have a type of constipation known as dyssynergic defecation (different parts of the anorectal area — pertaining to the anus and rectum — contract and relax at the wrong time).

    This type of constipation can be diagnosed by giving patients oral radiopaque markers that allow the doctor to view intestinal movements on an abdominal X-ray. Normally, people initiate a bowel movement by instinctively contracting the upper part of the rectum while relaxing the lower part. People with dyssynergic defecation constipation often do the opposite. Stools aren’t propelled through the colon, or they get “hung up” due to inappropriate muscle movements.

    People with this type of constipation usually are referred to a gastroenterologist, who often uses biofeedback, along with exercises such as Kegels (a type of pelvic-muscle exercise), to help them learn to relax and contract different parts of the anorectal area. They’re also taught not to strain during bowel movements — this decreases the force of intestinal contractions and impairs one’s ability to have a bowel movement.