This article is an excerpt from "Optimal Digestive Health: A Complete Guide" by John Furlong, N.D., edited by Trent W. Nichols, M.D. and Nancy Faass, MSW, MPH, and taken from the website

To practice truly preventive medicine, we have to know when to intervene. We need to be able to identify that crucial period when health is beginning to slip away, before the damage has been done.

We now have many of the pieces of the puzzle in our hands--the basis for truly preventive medicine. Basic yet sophisticated new lab tests are able to reflect the uniqueness of individual biology. These tests help us find inflammation, overly aggressive immune responses, poor digestion, and hormone problems; they all fit in the model of functional, preventive medicine. We also have the tools to intervene in these processes effectively with nutrients and herbs, minimizing the use of synthetic medications. It’s clear that medicine has made enormous progress in the development of pharmacology and technology, essential in heroic intervention against acute injury and disease. In contrast, when we’re working preventively, we find the time-honored relationships between what we eat, how we think, how much we exercise, and whether we reduce stress continue to be the most powerful modifiers of the disease process. We can adjust these aspects of our lives, knowing that the results will be naturally in accord with our physiology.

You are the person most likely to benefit from this new preventive medicine, being able to avert severe disease when the first signs of illness are present. Functional tests can help your doctors understand you better, enabling them to recommend therapies specific to your situation and get to the root cause of many kinds of illnesses. See your preventive or functional practitioner before things get out of hand and you’ll reap many benefits. You may even find you feel better than ever before!

The CDSA (Comprehensive Digestive Stool Analysis) This simple test, obtained from one to three stool samples, gives some twenty different measures. It assesses how food is utilized by the digestive system and the absorption of fats. The test also indicates the levels of bacteria and yeast, and the by-products of bacteria (both good and bad) in the colon. These assessments together provide a window into our digestion, an area we often overlook, but one essential for good health.

For instance, the test can show low levels of an enzyme from the pancreas called chymotrypsin. If this enzyme isn’t being secreted at the right level, our ability to absorb proteins may be impaired. In some cases, this is the cause of symptoms such as a failure to gain weight, gas, and bloating, and may relate to arthritis. The CDSA also reports on fats found in the stool. Although unabsorbed fats are normally quite low, when they are elevated, they can point to gallbladder problems, and difficulty in absorbing vitamins such as A, D, and E.

Intestinal Permeability
This test measures the degree of intestinal permeability in the small intestine. It answers the question “Has the intestinal wall become too permeable, allowing toxins, allergens, and bacteria to enter the bloodstream?” The procedure involves drinking a solution containing two harmless compounds, lactulose and mannitol. Lactulose is a larger molecule. Mannitol is very small. Because these molecules tend to pass through our system undigested, a urine collection can reflect how much of each substance is passing through the gut barrier into the bloodstream.

This is a test to identify the integrity of the small intestine and how well it’s likely to function and repair itself. So the information gained can help a physician determine how much wear and tear are affecting the small intestine. Periodically during treatment, this test can easily be retaken to gauge how well a person is responding to the therapy. If the test results show improvement with treatment, the doctor is on the right track!

Testing for Oxidative Stress
The test for oxidative stress is actually part of the complete detoxification profile, or it can be ordered separately. With this test, we’re challenging the body just a little by giving a small dose of aspirin. The test is used to measure free radicals that are produced as the body metabolizes the aspirin. Free radicals are highly active molecules that can be compared with a superball bouncing around in a room very rapidly, hitting walls, lights, whatever happens to be there.

The energy of the free radical is not necessarily a problem if there’s enough “cushioning” in the tissues surrounding its activity. Free radicals are generated from day-to-day activity such as exercise or metabolizing foods and generally don’t create any problem as long as there are adequate levels of antioxidants from the diet or a supplement.

The value of tests like the oxidative stress test is to detect excess production of free radicals and make changes before problems occur. Two of the chemicals that result from the aspirin challenge serve as markers of how much free radical damage this small dose of aspirin has generated. These chemicals can be measured in urine, and if those levels are high, we know the person is very susceptible to free radical activity. If the levels are normal, then we know he or she has adequate stores of antioxidants.

Author's Bio: 

JOHN FURLONG, N.D., is a naturopathic physician, trained at Bastyr University in Seattle. His experience in medicine ranges from hospital care to holistic health care. He was a founding member of a collaborative health center in Connecticut, where he provided services in nutritional, homeopathic, and botanical medicine and detoxification.

He also founded the People’s Health Alliance, a nonprofit organization promoting public education in natural approaches to healing. He is currently assistant director of education at the Great Smokies Diagnostic Laboratory.

Great Smokies Diagnostic Laboratory offers a variety of diagnostic testing, including tests described above; educational materials are available to both patients and practitioners on health, preventive medicine, and functional testing through their Client Services Department, 63 Zillicoa Street, Asheville, NC 28801-1074, or by calling
800-522-4762 or visiting their web site at <>.

Trent W. Nichols, M.D., is an internist, nutritionist, and gastroenterologist with more than 30 years of clinical experience. He is the founder and director of the Center for Nutritional Digestive Disorders and also the Advanced Magnetic Research Institute in Hanover, Pennsylvania.

Nancy Faass, MSW, MPH, is coauthor of several books on health and medicine, including "The Germ Survival Guide", "Boosting Immunity", and "Integrating Complementary Medicine into Health Systems". She lives in San Francisco.