InstalabStoolOMX™
Should you take a StoolOMX™ test?
This test is most useful if any of these apply to you.
46 Biomarkers Included
- Total Bile AcidsMeasures overall concentration of stool bile acids, indicating bile acid reabsorption/malabsorption
- Secondary Bile AcidsGet an early read on whether your gut bacteria are producing the right mix of digestive molecules linked to heart, liver, and colon health.
- Primary Bile AcidsThe most direct test for bile acid diarrhea, a fixable cause of chronic loose stools that hides on standard workups.
- Total Primary Bile AcidsAn emerging research-stage marker that may offer a window into how your liver and gut microbes work together, beyond what standard liver enzymes show.
- Cholic AcidA primary bile acid produced by the liver; stool levels reflect digestion/absorption dynamics.
- Chenodeoxycholic AcidAnother primary bile acid produced by the liver, relevant for bile acid pool dynamics.
- Taurochenodeoxycholic AcidGet an early read on how your gut is handling bile acids, a window into liver and digestive health that routine panels miss.
- Taurocholic AcidGet an early read on whether bile acid imbalance in your gut may be driving inflammation, dysbiosis, or metabolic stress.
- Glycochenodeoxycholic AcidGet an early read on bile acid metabolism that standard gut tests miss.
- Glycocholic AcidCatch hidden liver stress and bile flow problems before standard liver enzymes look abnormal.
- Hyocholic AcidGet an early read on whether your bile acid biology is supporting healthy metabolism, gut, and liver function.
- Total Secondary Bile AcidsGet an early read on whether your gut bacteria are making the protective compounds that influence colon and liver health.
- Deoxycholic AcidA secondary bile acid from bacterial conversion; stool levels help assess microbiome activity and bile acid handling.
- Isolithocholic AcidGet an exploratory read on how your gut microbes process bile acids, a pathway tied to sleep, metabolism, and cognition.
- Lithocholic AcidExplore how your gut bacteria shape a bile acid tied to fatty liver, gut inflammation, and metabolic risk.
- 12-Ketolithocholic AcidExplore whether your gut bacteria are reshaping bile in patterns linked to inflammation, blood sugar problems, and liver disease.
- 3-oxoDeoxycholic AcidGet an early read on whether your gut microbes are disrupting bile acid chemistry, a pattern linked to liver, kidney, and bowel disease.
- Ursodeoxycholic AcidGet an early read on the bile acid traffic between your liver and gut, a window into health that standard liver panels miss.
- 7-Ketolithocholic AcidGet an early read on how your gut microbes are reshaping bile acids, a window into liver and metabolic health that routine stool and liver tests miss.
- 7-Ketodeoxycholic AcidGet an early read on whether your gut microbes are disrupting bile acid chemistry, a pattern linked to liver, kidney, and bowel disease.
- Dehydrolithocholic AcidGet an early read on how your gut bacteria are reshaping bile acids, a signal that touches liver, kidney, and metabolic health.
- Hyodeoxycholic AcidGet an exploratory read on how your gut bacteria are shaping your liver, heart, and metabolic health.
- Alloisolithocholic AcidGet an early read on how your gut bacteria are reshaping bile acids in your colon.
- 3-Dehydrocholic AcidGet an early read on how your gut bacteria are reshaping your bile acid pool, a process tied to fatty liver progression.
- Glycolithocholic AcidGet an early read on how your gut bacteria and digestive system are working together, beyond what standard stool tests show.
- Glycoursodeoxycholic AcidAn exploratory bile acid read that may flag early metabolic, pregnancy, and liver risk that routine panels miss.
- Glycodeoxycholic AcidGet an early read on bile acid balance and gut-liver communication, beyond what standard liver tests can show.
- Taurolithocholic AcidGet an early read on the bile acid signal connecting your liver, gut bacteria, and immune system.
- Tauroursodeoxycholic AcidGet an early read on how your gut bacteria are reshaping your bile chemistry, a window into liver and metabolic health that routine stool tests miss.
- Taurodeoxycholic AcidGet an early read on how your liver and gut bacteria are working together, beyond what standard liver enzymes can show.
- Total Short Chain Fatty AcidsGet an early read on how well your gut microbes are working, beyond what any standard blood or stool panel shows.
- Total Saccharolytic Straight Chain Fatty AcidsGet an early read on whether your gut bacteria are producing the fuel that feeds your colon and helps regulate inflammation.
- Acetate %See whether your gut microbes are feeding your colon properly, and what that hidden process says about your metabolic health.
- Butyrate %See whether your gut bacteria are making enough of the fuel that keeps your colon lining healthy.
- Proprionate %Get an early read on how your gut microbes are handling fiber, and whether that output is linked to risks your standard labs miss.
- Valerate %Get an early read on whether your gut is making the lesser-known compound that fights off harmful bacteria like C. diff.
- AcetateGet an early read on whether your gut bacteria are making a balanced mix of fuel for your colon.
- Butyrate
- Proprionate
- Valerate
- CaproateGet an early read on how your gut bacteria are fermenting what you eat.
- Total Proteolytic Branched Chain Fatty AcidsGet an early read on whether your gut is fermenting more protein than fiber, a pattern tied to aging, low-fiber diets, and colon irritation.
- IsobutyrateGet an early read on whether your gut microbes are fermenting protein instead of fiber, a pattern linked to dysbiosis and aging.
- IsovalerateGet an early read on how your gut bacteria are handling protein, a window standard digestive labs do not offer.
- 2-MethylbutyrateGet an early read on how your gut bacteria are handling protein, a signal that routine stool tests do not capture.
- IsocaproateGet an early read on whether C. difficile bacteria are actively fermenting in your gut.
About StoolOMX™
Your liver makes bile acids to digest fat, but what happens to those bile acids once they reach your colon tells a different story. Gut bacteria transform them, and the pattern of transformation reveals whether your microbiome is working for you or against you. A standard stool test does not capture this. The StoolOMX panel measures 25 bile acids and 9 short-chain and branched-chain fatty acids in a single stool sample, giving you a metabolic map of what your gut bacteria are actually producing.
This matters because the chemical byproducts your gut bacteria generate act directly on the colon wall. Some protect it. Some damage it. The balance between protective and harmful byproducts is linked to conditions ranging from chronic diarrhea and irritable bowel syndrome (IBS) to inflammatory bowel disease (IBD) and colorectal cancer risk. The StoolOMX panel reads that balance.
What This Panel Reveals
The panel covers two distinct but connected metabolic systems: bile acid metabolism and bacterial fermentation. Together, they answer questions that neither system alone can address.
Bile Acid Metabolism
Your liver produces two primary bile acids, cholic acid and chenodeoxycholic acid, and pairs them with amino acids (glycine or taurine) before releasing them into the small intestine. About 95% get reabsorbed and recycled. The remaining 5% enter the colon, where bacteria convert them into secondary bile acids like deoxycholic acid and lithocholic acid. This panel measures the full spectrum: primary, secondary, amino acid-paired, and modified forms.
The ratio of primary to secondary bile acids is a direct readout of microbial metabolic activity. When bacteria are doing their job, most fecal bile acids are secondary. When antibiotic use, dysbiosis (an imbalance in gut bacteria), or rapid transit disrupts that conversion, primary bile acids and those still paired with amino acids accumulate in stool. A systematic review found that roughly 25% to 33% of people diagnosed with diarrhea-predominant IBS (IBS-D) actually have excess fecal bile acids driving their symptoms, a condition called bile acid diarrhea.
Elevated total fecal bile acids, particularly elevated primary bile acids, stimulate water and electrolyte secretion in the colon, causing watery diarrhea. Identifying this pattern changes treatment entirely, because bile acid sequestrant medications can resolve symptoms that standard IBS therapies miss.
Bacterial Fermentation Products
When gut bacteria ferment dietary fiber, they produce short-chain fatty acids (SCFAs): acetate, butyrate, and propionate are the three main ones. Butyrate is the primary fuel for the cells lining your colon (colonocytes). Without adequate butyrate, these cells lose their energy supply, barrier function weakens, and inflammation can take hold. Studies in people with ulcerative colitis consistently show reduced fecal butyrate concentrations compared to healthy controls.
The panel also measures branched-chain fatty acids (BCFAs) like isobutyrate and isovalerate. These come from a different process: bacterial breakdown of protein rather than fiber. A high BCFA level, or a low SCFA-to-BCFA ratio, signals that your gut bacteria are doing more protein fermentation and less fiber fermentation. Protein fermentation produces compounds associated with gut inflammation and mucosal damage. The SCFA/BCFA ratio is essentially a scorecard for how well your diet is feeding your beneficial bacteria.
How to Read Your Results Together
Individual markers tell you something. Patterns tell you much more. Here are the interpretation patterns that matter most.
| Pattern | What It Suggests | Next Steps |
|---|---|---|
| High total fecal bile acids with elevated primary bile acids | Bile acid diarrhea or malabsorption: bile acids are not being properly reabsorbed in the small intestine | Discuss bile acid sequestrant therapy; consider SeHCAT (a bile acid absorption scan) or serum C4 (a blood marker of bile acid production) testing if available |
| High secondary bile acids (especially deoxycholic acid) with low butyrate | A microbiome environment favoring colon irritation without protective counterbalance, associated with increased colorectal cancer risk | Increase dietary fiber intake; consider colonoscopy screening discussion |
| Low total SCFAs with low butyrate | Reduced beneficial bacterial fermentation; fiber intake may be too low, or butyrate-producing bacteria may be depleted | Increase prebiotic fiber; assess for antibiotic history or dysbiosis |
| Low SCFA/BCFA ratio | Excess protein fermentation relative to fiber fermentation, signaling a diet or microbiome shift toward protein breakdown | Increase soluble fiber, reduce excess protein; retest in 3 to 6 months |
When total bile acids are elevated but secondary bile acids dominate, the microbiome is actively converting primary bile acids, which is normal. But persistently high deoxycholic acid specifically has been associated with increased risk of colorectal adenomas (precancerous polyps). Research has linked elevated deoxycholic acid levels to a higher likelihood of adenoma development and recurrence, supporting the value of monitoring this bile acid over time.
When Results Can Be Misleading
Several factors can shift bile acid and SCFA levels without reflecting a true underlying problem. Antibiotic use within the past 4 to 6 weeks can dramatically reduce secondary bile acid conversion and SCFA production, because the bacteria responsible are suppressed. A single course of broad-spectrum antibiotics can reduce fecal butyrate for weeks.
Diet in the 48 to 72 hours before collection matters. A sudden increase in fiber will temporarily raise SCFAs. A very low-fiber or very high-protein meal pattern will lower the SCFA/BCFA ratio. Bile acid sequestrant medications (cholestyramine, colesevelam) will lower fecal bile acids by design, so results under treatment reflect the medication effect rather than baseline physiology.
Rapid intestinal transit, from any cause, increases fecal bile acid excretion because there is less time for reabsorption. If you have active diarrhea from an acute infection, bile acid levels may be transiently elevated without indicating a chronic malabsorption problem.
Tracking Over Time
A single snapshot of your fecal metabolites has value, but serial testing is where the panel becomes most useful. If you change your diet, start a prebiotic or probiotic, or begin bile acid therapy, repeating the panel in 3 to 6 months shows whether the intervention is actually shifting your metabolite profile in the right direction.
For someone tracking colorectal cancer risk, monitoring the deoxycholic acid level and the SCFA/BCFA ratio over time provides a functional readout of whether dietary and lifestyle changes are producing a more protective colonic environment. A rising butyrate level and a falling deoxycholic acid level together suggest that your microbiome is moving in a favorable direction.
Tracking also helps distinguish a transient disruption (post-antibiotic, post-illness) from a persistent metabolic pattern that warrants intervention. One abnormal result is a signal. Two or three abnormal results across months are a trend.