Need Help? 1-800-476-0016

7 Weird Stool Odor Facts

Published on , Last Updated on August 10, 2017

Stool odor stinks!

Let’s face it, stool odor can be best summed up in two words: it stinks. Stool odor is a byproduct of digestion. Volatile compound, such as methyl sulfide compounds, skatole and indole, are produced and are responsible for stool’s odor component. [1] Individual stool odor is as unique as each person’s fingerprints and varies with diet and internal body chemistry, but the subtle differences of stool odor can reveal a great deal about overall health. The following weird facts may provide valuable insight as to the importance of stool odor awareness. Or they just may be weird.

1. Humans Relentlessly Try to Neutralize It

Bathroom sprays, candles, matches… all common restroom tools used to counteract the olfactory-offending odor of a healthy bowel movement. Can anything be done to reduce the smell at the source? Is there anything that can be taken to dampen the smell-producing portion of digestion? In the quest to answer that question, researchers have come to a few conclusions. Activated charcoal — while helpful at reducing odors in air filtration devices — offers no odor-reduction qualities when consumed. [2] Inquiries into the efficacy of chlorophyll have been mixed. Although a randomized, double-blind, 1989 study found that chlorophyll doesn’t help, a separate study of 62 nursing home patients found that chlorophyll tablets were helpful at controlling fecal odor. [3] [4] Bismuth subsalicylate, also known as Pepto-bismol, binds to hydrogen sulfide and may help control fecal odor, up to 95% in some cases. [5] Personally, I’ve found that regular colon cleansing and maintaining a healthy balance of intestinal flora to be very effective.

2. Stool Odor May Indicate Irritable Bowel Disease

Typically, an IBD diagnosis comes from an evaluation of multiple symptoms, and one of them can be extremely foul smelling stool. A foul odor is often the result of bacterial and microbial changes in the digestive tract. [6] This also applies to the presence of IBS in kids. [7] Even rotavirus, celiac disease, cystic fibrosis, and intestinal infections produce a characteristic odor. [8] [9]

3. There May Be Another Reason for Dogs to Take a Sniff

A labrador retriever can be trained to smell cancer with incredible accuracy. A Japanese study had a Labrador smell a range of stool samples from individuals with colorectal cancer and from a control group of healthy individuals. The dog identified, with 97% accuracy, the sample from the individual with CRC. [10] Based on this study, it appears cancer has a smell, and trained dogs can detect it.

4. The Smell Can Linger… a LONG Time

Paleontology is the study of prehistoric life, and working with fossils is one of the job perks. Fossils can provide a glimpse into the past, and fossilized feces, known as coprolites, can tell us a lot about prehistoric diets… but can they also still have a small? Well, a molecular level — yes. Using an analysis method known as fecal odor grams, human coprolites from 6400 BC have been analyzed and found to contain odors of grass, green leaves, licorice, meat, and corn. [11] No trace of GMO’s!

5. Foul Gas… or Essential Compound?

Hydrogen sulfide contributes to the bad odor in bad breath, gas, and feces. Researchers know that it occurs naturally and in high concentrations in human tissue and the brain. This has led to consideration of its importance as a signaling molecule necessary for overall bodily function. Except, it doesn’t occur in a free gaseous form in the blood stream — the essential form which makes molecules such as nitric oxide bioavailable. [12] Toxic or essential? The research continues, although the odor of hydrogen sulfide may influence your opinion…

6. Stool Odor Won’t Reveal Beaver Fever

While stool odor may help identify cancer, one study found it doesn’t tell us anything about harmful organism infestation in the digestive tract. Beaver fever, aka giardiasis, results from a single celled organism that’s found its way into the digestive tract. Spread from fecal matter to the mouth, this little bug reproduces and coats the lining of the small intestine. In an effort to evaluate the options for diagnosis, researchers tested stool odor as a means to identify infestation. A study included 513 children, 378 who were exposed. Unfortunately, few differences between healthy and exposed children were detected. [13]

7. The Greater the Stress, the Greater the Stink

It’s no secret that stress produces many negative health effects, but did you know it may actually make your stool more stinky? Researchers at the Tokyo University of Agriculture and Technology exposed mice to various stressors and then evaluated their feces for changes in odor intensity. The result? Stress concentrated and worsened stool odor. Bottom line — stress stinks. [14]

Got a stool odor fact we forgot? Please leave a comment below and share it with us!

-Dr. Edward F. Group III, DC, ND, DACBN, DCBCN, DABFM


  1. Gas-chromatographic and mass-spectrometric analysis of the odor of human feces. Gastroenterology. 1987 Dec;93(6):1321-9.
  2. Suarez FL, Furne J, Springfield J, Levitt MD. Failure of activated charcoal to reduce the release of gases produced by the colonic flora. Am J Gastroenterol. 1999 Jan;94(1):208-12.
  3. Christiansen SB, Byel SR, Strømsted H, Stenderup JK, Eickhoff JH. [Can chlorophyll reduce fecal odor in colostomy patients?]. Ugeskr Laeger. 1989 Jul 3;151(27):1753-4.
  4. Young RW, Beregi JS Jr. Use of chlorophyllin in the care of geriatric patients. J Am Geriatr Soc. 1980 Jan;28(1):46-7.
  5. Suarez FL, Furne JK, Springfield J, Levitt MD. Bismuth subsalicylate markedly decreases hydrogen sulfide release in the human colon. Gastroenterology. 1998 May;114(5):923-9.
  6. Probert CS. Role of faecal gas analysis for the diagnosis of IBD. Biochem Soc Trans. 2011 Aug;39(4):1079-80. doi: 10.1042/BST0391079.
  7. Schmitz J, Arhan P, Doye C, Faverdin C. [Irritable bowel syndrome in children]. Gastroenterol Clin Biol. 1990;14(5 ( Pt 2)):54C-57C.
  8. Poulton J, Tarlow MJ. Diagnosis of rotavirus gastroenteritis by smell. Arch Dis Child. 1987 Aug;62(8):851-2.
  9. Mellingen KM, Midtun A, Hanevik K, Eide GE, Søbstad Ø, Langeland N. Post epidemic giardiasis and gastrointestinal symptoms among preschool children in Bergen, Norway. A cross-sectional study. BMC Public Health. 2010 Mar 26;10:163. doi: 10.1186/1471-2458-10-163.
  10. Sonoda H, Kohnoe S, Yamazato T, Satoh Y, Morizono G, Shikata K, Morita M, Watanabe A, Morita M, Kakeji Y, Inoue F, Maehara Y. Colorectal cancer screening with odour material by canine scent detection. Gut. 2011 Jun;60(6):814-9. doi: 10.1136/gut.2010.218305. Epub 2011 Jan 31.
  11. Moore JG, Krotoszynski BK, O’Neill HJ. Fecal odorgrams. A method for partial reconstruction of ancient and modern diets. Dig Dis Sci. 1984 Oct;29(10):907-11.
  12. Tangerman A. Measurement and biological significance of the volatile sulfur compounds hydrogen sulfide, methanethiol and dimethyl sulfide in various biological matrices. J Chromatogr B Analyt Technol Biomed Life Sci. 2009 Oct 15;877(28):3366-77. doi: 10.1016/j.jchromb.2009.05.026. Epub 2009 May 21.
  13. Mellingen KM, Midtun A, Hanevik K, Eide GE, Søbstad Ø, Langeland N. Post epidemic giardiasis and gastrointestinal symptoms among preschool children in Bergen, Norway. A cross-sectional study. BMC Public Health. 2010 Mar 26;10:163. doi: 10.1186/1471-2458-10-163.
  14. Sakuma K, Hayashi S, Yasaka Y, Nishijima H, Funabashi H, Hayashi M, Matsuoka H, Saito M. Analysis of odor compounds in feces of mice that were exposed to various stresses during breeding. Exp Anim. 2013;62(2):101-7.

Posted In: Colon Health Blog
  • Everyusernametaken

    Thanks for this but you didn’t talk about the different types of fecal odor (smell frequency/chart).

Oxy-Powder® Detox/Cleansing Learn More Quick Help GHC on the Web
Follow us on the web:
Learn More
Quick Help
GHC on the Web
Follow us on the web:
Global Healing Center | 2040 North Loop West, Ste. 108 | Houston, Texas 77018
Telephone: 713-476-0016 | Toll Free: 1-800-476-0016 | Fax: 713-476-0017

DISCLAIMER: These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.

All testimonials and product reviews are authentic from actual customers. Documentation is available for legal inspection. Product reviews are within range of typicality.

Information and statements made are for education purposes and are not intended to replace the advice of your treating doctor. Global Healing Center does not dispense medical advice, prescribe, or diagnose illness. The views and nutritional advice expressed by Global Healing Center are not intended to be a substitute for conventional medical service. If you have a severe medical condition or health concern, see your physician. This Web site contains links to Web sites operated by other parties. Such links are provided for your convenience and reference only. We are not responsible for the content or products of any linked site or any link contained in a linked site. Global Healing Center does not adopt any medical claims which may have been made in 3rd party references.

© Copyright 1998 - 2018 | All Rights Reserved