Melanosis coli: Symptoms, causes, treatment, and more Health ConditionsHealth ConditionsAlzheimer's & DementiaAnxietyArthritisAsthma & AllergiesBreast CancerCancerCardiovascular HealthCOVID-19Dermatology & SkincareDiabetesEnvironment & SustainabilityExercise & FitnessEye HealthHeadache & MigraineHealth EquityHIV & AIDSHuman BiologyInflammatory Bowel DiseaseLeukemiaLGBTQIA+Men's HealthMental HealthMultiple Sclerosis (MS)NutritionParkinson's DiseasePsoriasisSexual HealthWomen's HealthDiscoverNewsLatest NewsOriginal SeriesMedical MythsHonest NutritionThrough My EyesNew Normal HealthPodcastsHow to understand chronic painWhat is behind vaccine hesitancy?The amazing story of hepatitis C, from discovery to cureNew directions in dementia researchCan psychedelics rewire a depressed, anxious brain?Why climate change matters for human healthToolsGeneral HealthDrugs A-ZHealth HubsHealth ToolsBMI Calculators and ChartsBlood Pressure Chart: Ranges and GuideBreast Cancer: Self-Examination GuideSleep CalculatorHealth ProductsAffordable Therapy OptionsBlood Pressure MonitorsDiabetic SuppliesFitness TrackersHome GymsGreen Cleaning ProductsHow to Shop for CBDQuizzesRA Myths vs FactsType 2 Diabetes: Managing Blood SugarAnkylosing Spondylitis Pain: Fact or FictionConnectAbout Medical News TodayWho We AreOur Editorial ProcessContent IntegrityConscious LanguageNewslettersSign UpFollow UsMedical News TodayHealth ConditionsDiscoverToolsConnectSubscribe What to know about melanosis coliMedically reviewed by Kelsey Trull, PA-C — By Suzy Davenport on September 28, 2022Melanosis coli, also known as pseudomelanosis coli, is a benign pigment disorder in which the lining of the large intestine, or colon, turns black or brown. The condition is benign, meaning that it does not pose any danger to a person’s health. Some research suggests that melanosis coli may even facilitate the diagnosis of benign and cancerous colon polyps. This article explores the signs and symptoms of melanosis coli, as well as its causes, diagnosis, treatment, and prevention. It also discusses the outlook for people living with the condition. Signs and symptoms Share on PinterestSEBASTIAN KAULITZKI/SCIENCE PHOTO LIBRARY/Getty ImagesMelanosis coli is a pigment disorder that does not cause any symptoms, so a person might never know that they have the condition. A doctor will often only detect melanosis coli if they see it when carrying out a colonoscopy or sigmoidoscopy for another reason. A colonoscopy is a procedure that involves the use of a colonoscope. This device consists of a flexible tube with a camera and light attached, which allows the doctor to check for inflammation and other abnormalities in the colon and rectum. A sigmoidoscopy is a similar, less intrusive procedure that allows the doctor to view only the lower part of the colon. Causes Doctors typically detect melanosis coli in individuals over the age of 45 years, although the condition can also occur in younger people. It appears to affect males and females equally. Below are some possible causes of melanosis coli. Simulant laxative use Melanosis coli often occurs as a result of using stimulant laxatives for an extended period. This class of laxatives irritates the intestinal nerves, causing the intestines to contract and push stool out of the body. There are several types of stimulant laxatives. Anthraquinones are the type most associated with melanosis coli. Examples include:sennaaloerhubarbcascara sagradabuckthorn A 2015 case study notes that anthraquinones can trigger the death of mucosal cells within the lining of the colon. The dead cells become discolored, resulting in abnormally pigmented areas of colon tissue. Topical psoriasis treatment Melanosis coli can also develop in response to using topical psoriasis treatments containing a natural derivative of anthraquinone called anthralin. Diet Anthraquinone is a plant compound that is present in certain vegetables and herbs. A person may develop melanosis coli due to the excessive consumption of herbal products containing anthraquinones. NSAID use In a 2017 study investigating 219 people with melanosis coli, two participants had no history of laxative use but regularly used nonsteroidal anti-inflammatory drugs (NSAIDs). Examples of NSAIDs include:aspirinibuprofennaproxen Inflammatory bowel disease A 2022 review notes that melanosis coli may be present in some individuals with a form of inflammatory bowel disease (IBD) called ulcerative colitis. Link to colon cancer A 2015 case study notes that melanosis coli is a benign condition that is not associated with colon cancer. The authors add that melanosis coli may, in fact, help doctors detect both benign and malignant colon polyps, as these growths do not take on the darker pigmentation of the surrounding tissue. A 2018 study compared polyp detection rates and colon cancer diagnoses in participants with and without melanosis coli. The researchers found that the condition was associated with enhanced polyp detection but not increased diagnosis of colorectal cancer. Diagnosis Most melanosis coli diagnoses occur during or after a colonoscopy or sigmoidoscopy for another reason. A doctor should be able to detect the characteristic pigmentation changes during either of these procedures. However, they may take a tissue biopsy to confirm the findings and rule out more serious medical conditions. Treatment According to a 2020 review, melanosis coli is a reversible condition. The authors state that a person who has melanosis coli and takes anthraquinone laxatives should stop taking the laxatives to help reverse the condition. The authors also state that surgery should only be a consideration in cases where the melanosis coli occurs alongside a serious malignancy. A 2021 case study reported on a woman who developed melanosis coli due to laxative use following a treatment called peritoneal dialysis. In this case, the treatment for melanosis coli involved stopping the laxatives and taking a probiotic. Prevention It may not always be possible to prevent melanosis coli. However, avoiding laxative use could help reduce the risk of developing the condition. People usually take laxatives due to constipation. A person can take steps to help prevent constipation. These include:drinking plenty of waterrefraining from drinking alcoholeating plenty of high fiber foodstaking a fiber supplementpartaking in regular physical activitytrying to have bowel movements at the same time every daystopping taking certain medications and supplements that cause or contribute to constipation, but only if a doctor states that it is safe to do so If a person continues to experience constipation after trying all of the above, they should consult a doctor. The doctor may run tests to determine the cause, and they may recommend prescription treatments. Surgery may be an option if the constipation relates to a lack of function in the colon muscles or a rectal prolapse. Outlook Melanosis coli is a pigmentation condition that does not cause any symptoms. The condition is benign, meaning that it is not associated with any risk to a person’s health. Most cases of melanosis coli are due to the regular use of anthraquinone laxatives to treat chronic constipation. A person who experiences chronic constipation may develop symptoms and complications related to the constipation, such as hemorrhoids and fecal impaction. Summary Melanosis coli is a benign condition that causes black or brown discoloration of the colon wall. It usually occurs as a result of using anthraquinone laxatives. People with melanosis coli may never know that they have the condition, as it does not cause any symptoms. Most doctors diagnose the condition during or following colonoscopy or sigmoidoscopy procedures for an unrelated reason. Researchers have not identified any association between melanosis coli and colon cancer. In fact, some research suggests that melanosis coli can help doctors detect benign and malignant colon polyps. Last medically reviewed on September 28, 2022GastroIntestinal / Gastroenterology 10 sourcescollapsedMedical News Today has strict sourcing guidelines and draws only from peer-reviewed studies, academic research institutions, and medical journals and associations. We avoid using tertiary references. We link primary sources — including studies, scientific references, and statistics — within each article and also list them in the resources section at the bottom of our articles. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.Baker, F. A., et al. (2018). Melanosis coli: A helpful contrast effect or a harmful pigmentation?https://journals.sagepub.com/doi/full/10.1177/1179552218817321Colonoscopy. (2017).https://www.niddk.nih.gov/health-information/diagnostic-tests/colonoscopyConstipation. (2020).https://www.nhs.uk/conditions/constipation/Cowley, K., et al. (2015). Who turned out the lights? An impressive case of melanosis coli.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4612746/Liu, Z. H., et al. (2017). Melanosis coli: Harmless pigmentation? A case-control retrospective study of 657 cases.https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0186668Melanosis coli. (n.d.).https://www.sciencedirect.com/topics/medicine-and-dentistry/melanosis-coliNesheiwat, Z., et al. (2022). Melanosis coli.https://www.ncbi.nlm.nih.gov/books/NBK493146/Treatment for constipation. (2018).https://www.niddk.nih.gov/health-information/digestive-diseases/constipation/treatmentYang, N., et al. (2020). Melanosis coli: A comprehensive review[Abstract].https://www.sciencedirect.com/science/article/abs/pii/S2444382420300547Zakaria, N. F., et al. (2021). Melanosis coli in a peritoneal dialysis patient: A case report.https://link.springer.com/article/10.1186/s13256-021-02895-2FEEDBACK:Medically reviewed by Kelsey Trull, PA-C — By Suzy Davenport on September 28, 2022 Latest newsWhat sets 'SuperAgers' apart? Their unusually large neuronsOmega-3 may provide a brain boost for people in midlifeSeasonal affective disorder (SAD): How to beat it this fall and winterCDC: Monkeypox in the US 'unlikely to be eliminated in the near future'Why are more women prone to Alzheimer's? New clues arise Related CoverageWhat to know about colon pain Many conditions can cause colon pain, including constipation, diarrhea, irritable bowel syndrome, and colorectal cancer. Learn more here.READ MOREWhat to know about the descending colonMedically reviewed by Alana Biggers, M.D., MPH What is the descending colon? Read on to learn about this section of the bowel, including its anatomy and function and what conditions can affect it.READ MOREWhat is necrotizing enterocolitis? Necrotizing enterocolitis is a gastrointestinal condition that primarily affects premature newborns. Learn more about it here.READ MORE