Introduction

Constipation can be defined as infrequent or hard pellet stools, or difficulty in evacuating stool. Passing one or more soft, bulky stools every day is a desirable goal. While troublesome, constipation is not usually a serious disorder. However, there may be other underlying problems causing constipation and, therefore, testing is often recommended.

What Causes Constipation?

The stomach churns and mixes food so it can be digested. The near-liquid food then enters the small intestine which extracts calories, minerals and vitamins. The small intestine ends in the right-lower abdomen where it enters the colon. The colon, or large bowel, is 5 to 6 feet long. Its function is to withdraw water from the liquid stool, so that by the time it reaches the rectum, there is a soft formed stool. If an excessive amount of water is extracted, the stool can become hard and difficult to expel.

Constipation is often caused by a lazy colon that does not contract properly and fails to move the stool to the rectum. The colon also can become spastic and remain contracted for a prolonged time. In this case, stool cannot move along. Too much water is absorbed and hard pellet-like stool develops. Constipation also can result from a mechanical obstruction, such as tumors or advanced Diverticulosis, a disorder which can distort and narrow the lower left colon. Other conditions that can produce a sluggish, poorly contracting bowel include Irritable Bowel Syndrome, pregnancy, certain drugs, thyroid hormone deficiency, chronic abuse of laxatives, travel, and stress.

Diagnosis

The patient’s medical history is most important in diagnosing the cause of constipation. The physician will perform a physical exam and obtain certain blood tests. A barium x-ray exam of the lower bowel or colon  may be warranted. In addition, a sigmoidoscopy exam (using a lighted, flexible endoscope) is necessary to rule out a mechanical blockage of the lower bowel, such as a tumor. This exam allows the physician to view the bowel wall and obtain biopsies (tissue samples) of any suspicious areas. Colonoscopy may be indicated. This is the visual exam of the inside of the entire colon using a flexible endoscope. The exam is usually performed under mild sedation. A marker test may be done whereby the patient swallows a capsule containing markers. Some days later an x-ray is taken to analyze the pattern and distribution of markers in the colon. In some cases, pressure measurements of the rectum and lower colon can provide valuable information. This exam is called manometry.

Treatment

Because there are many causes of constipation, treatment depends on the physician’s findings and diagnosis. After serious problems are excluded, chronic constipation usually responds to simple measures, such as adding fiber, bran or a bulking agent to the diet.

General guidelines for treating constipation include: eating regularly, drinking plenty of liquids each day, and regular walking or aerobic exercise. In particular, individuals should respond to the urge to defecate. Retaining stool at this point will aggravate the condition.

Diet and Fiber

Increased dietary fiber is almost always an important part of any dietary program. You are referred to High Fiber Diet for details. The short version is that there are two main types of fiber, insoluble and soluble, and almost every plant has some of each. Insoluble fiber does not dissolve in water, is not acted on by colon bacteria and does not create colon gas. It is an important fiber because it hangs on to water within the colon, promoting a large, bulky stool and improved regularity. The second type of fiber is soluble, meaning it does dissolve in water and is fermented by colon bacteria. Some of these bacteria create colon gas.

Most plants have both fibers to varying degrees. As examples, the fibers in wheat are mostly insoluble while those in oats and beans are mostly soluble.  Prebiotics, especially inulin and oligofructose, are recently discovered soluble fibers.  These fibers have had a great deal of research done on them lately and multiple, significant health benefits have been found to occur. Still, they are soluble and, as such, do produce colon gas just like all soluble fibers will if too much is taken.

The key is to get a good balance of these fibers. The recommended total fiber intake per day is 25-35 grams, depending on your sex, age and weight. At this level, multiple health benefits occur. However, if excess colon gas and flatus are problems, then cut back on soluble fiber first. 

The section on Fiber Content of Foods lists the amount of soluble and insoluble fiber in most foods.

Prebiotics

Prebiotics are the soluble food fibers that feed the healthy bacteria in the colon. The term was coined in 1995, so the field is rather new. Researchers are evaluating many prebiotics, but only inulin and oligofructose have shown consistent results. Please refer to my essay, Introduction to Prebiotics and Prebiotics for details. The key thing that these two prebiotics (and hopefully, others) do is stimulate the colon’s good bacteria to grow. Inulin and oligofructose can also make the colon more acidic.

Methane Constipation

There is some early research that suggests that the colon gas, methane, may promote constipation. Prebiotic plant fibers can increase the acidity of the colon to an extent that these particular methane producing bacteria may stop growing. Were I still in practice, I would encourage my constipation patient to eat foods containing prebiotics or use a prebiotic supplement in gradually increasing doses – 1 gram a day for several days, then 2 grams and so forth. If excessive colon gas and bloating or cramps occur before constipation improves, then the diet test did not work. If it did, then you should find the amount of prebiotic soluble fiber that works for you by evaluating the malodorous sulfide smell of your flatus. The bacteria that make methane do not grow in an acid environment. Likewise, those that make the malodorous sulfide gases in colon gas do not grow in an acid environment. If your flatus has no or little smell, your colon may be at the right acidity to prevent the methane producing bacteria from growing. See references at end.

Exercise

Regular exercise, even walking, can help prevent constipation.

Do Laxatives Help?

There are two types of laxatives: stimulants (chemical) and saline (liquid or salt). They occasionally help temporary constipation.  However, chronic use of laxatives, especially stimulant laxatives is discouraged because the bowel becomes dependent upon them. Bowel regularity should occur without laxatives. An occasional enema is preferable over the chronic use of laxatives.

Surgery

With certain medical conditions such as severe diverticulosis or extreme constipation in children, surgery may be required.

Bowel Retraining Program

1. Do not use laxatives long term.
2. Eat a diet high in roughage, such as bran cereals, fruits and leafy vegetables (click Fiber Content of Foods).
3. Drink six (6) ounces of prune or apricot juice each morning.
4. Eat two (2) large servings of stewed fruit each day.
5. Eat a normal breakfast.
6. Set aside 15 minutes after breakfast to sit on the toilet, but do not strain to have a bowel movement.
7. If you do not have a bowel movement by the third day, use an enema and repeat the above steps.
8. Consider the use of a fiber prebiotic preparation.

Summary

Constipation usually is a short-term disorder which can be controlled by simple measures. However, the condition may reflect a more serious underlying disorder that can only be detected and treated by the physician. For chronic constipation, it is important that the patient understands how this occurs. Adequate dietary fiber is usually the first and perhaps the only step that needs to be taken.