The comprehensive digestive stool analysis (CDSA) is a stool test offered by various labs that may help you and your health care provider uncover underlying causes for chronic symptoms and illness, both digestive and systemic. As with most functional laboratory tests it is most often used when conventional diagnostic testing has failed to provide an explanation for a patient's health concerns, however it can also provide early indication of the development of conditions such as pancreatitis, inflammatory bowel disease (IBD), and colon cancer risk, for example.
The test requires the patient to collect a single stool sample at home and mail it back to the lab in the container and envelope provided. The sample is then analyzed and the results and interpretive report returned to the patient's health care provider.
What the CDSA Measures
The CDSA is indeed "comprehensive" and looks at quite a large number of different markers of gastrointestinal health. These fall into several groups:
The pancreas is the organ responsible for secreting the vast majority of digestive enzymes into the GI tract which act on food to break it down into smaller and smaller pieces which can ultimately be absorbed by the body as individual nutrients(the process of digestion). The CDSA measures substances such as chymotrypsin (a digestive enzyme) which give an idea of general pancreatic function and how well the digestive process is working. Additionally putrefactive short-chain fatty acids (SCFAs) are measured. These are produced by certain bacteria in the colon and would be high if digestion was poor in which case the bacteria would have a rich supply of food themselves. Finally the stool sample is examined for evidence of undigested meat and vegetable fibres which obviously would indicate poor digestion.
A range of markers are tested for to determine if the body is absorbing nutrients from food correctly. These markers are generally fats/lipids which are easy to detect and provide a good overal picture of absorptive capacity - they include triclycerides, long-chain fatty acids, cholesterol, phospholipids, and total faecal fat. If these are found in high levels in the stool it could indicate poor digestion due to enzyme or bile deficiency, damage (e.g. inflammation) to the absorptive lining of the small intestine, or a fast transit time (e.g. diarrhoea).
These mainly focus on factors influenced by the gut microflora, the bacteria, yeast, and other microorganisms that inhabit the gut. The CDSA measures things such as levels of beneficial SCFAs and the relative amounts of the different types, stool pH, and beta-glucuronidase. Beneficial SCFAs are produced by beneficial bacteria such as Bifidobacteria and Lactobacilli as they metabolise dietary fibre and serve to maintain a stool pH unfavourable to pathogens (slightly acidic), provide fuel to intestinal cells, and reduce inflammation, amongst other functions. Beta-glucuronidase is an enzyme produced by the human body as well as by certain unfavourable gut bacteria. High levels can lead to increased recirculation of toxins, steroid hormones, drugs, and cancer-causing substances in the body.
The lab takes cultures from the stool sample to determine levels of microorganisms present in the GI tract. Gut microflora tested for include both beneficial bacteria such as Bifidobacterium, Lactobacilli, and beneficial strains on E.coli, additional bacteria such as Streptococcus, bacteria which may become pathogenic at high levels including Citrobacter, Enterobacter, and Klebsiella, and bacteria which are considered pathogens at any level including pathogenic E.coli strains, Campylobacter, and Clostridium. As well as bacteria levels of yeasts and fungi such as Candida are also tested for. Most labs in addition to detecting potentially pathogenic microoganisms will provide information on the best prescription and natural substances to eradicate them based on sensitivity testing.
Various indicators of gut immunity are tested for including secretory IgA (sIgA), the antibody responsible for protecting the mucous membranes of the body (e.g. the GI tract) from pathogens. Other markers of gut immunity include lactoferrin which binds iron and prevents it being used by undesirable gut microflora, and various substances released bywhite blood cells (WBCs) which indicate inflammation at high levels.
Finally the stool sample is examined for blood, mucous, and colour to provide further information about GI health.
Uses for the CDSA
The CDSA has many uses but is most often used by integrative or complementary/alternative medicine practitioners for the diagnosis of the underlying causes of chronic health problems including irritable bowel syndrome (IBS) and chronic fatigue syndrome (ME/CFS), particularly problems with digestion and absorption, food allergies/intolerances, and disturbances in the gut microflora such as small intestinal bacterial overgrowth (SIBO), Candida overgrowth, and deficiency of beneficial/probiotic bacteria.
In some instances the CDSA may indicate the need for further testing for serious disease such as Cancer, IBD, or coeliac disease.