- Melanosis Coli (Pseudomelanosis Coli) Center
- Take the Pancreatitis Quiz
- Boost Digestive Health
- Digestive Distress Slideshow: Problem Foods to Avoid
- Patient Comments: Melanosis Coli - Symptoms and Diagnosis
- Find a local Gastroenterologist in your town
What is melanosis coli?
Melanosis coli is a condition usually associated with chronic laxative use in which dark pigment is deposited in the lamina propria (one of the lining layers) of the large intestine (colon). The pigment deposition results in a characteristic dark brown to black discoloration of the lining of the large intestine. This condition is sometimes called pseudomelanosis coli because the pigment deposits consist of a pigment known as lipofuscin and do not contain melanin as implied by the term "melanosis." Lipofuscin is a cellular pigment that forms when cells are destroyed, often called "wear and tear" pigment that can be found throughout the body.
The dark color of the intestinal lining may be uniform or patterned, and the discoloration may be slight or very pronounced. The intensity and pattern of the discoloration may even vary among different sites in the colon of a single person. The condition may also be reversed upon discontinuation of laxative use. In some cases, the wall of the colon appears normal to the eye, but microscopic evaluation of biopsies by a pathologist reveals areas of pigment in the colon's lining. The pigment in melanosis coli does not accumulate in polyps or tumors of the large intestine.
What causes melanosis coli?
Melanosis coli usually results from chronic use of laxatives of the anthranoid group. Some examples of anthranoid laxatives are senna (sennosides; Senocot, Senokot EXTRA and others) and rhubarb derivatives. Many of these laxatives have been in use for hundreds of years. In 1997, the U.S. Food and Drug Administration (FDA) banned the use of the popular anthranoid laxative phenolphthalein due to fears that it might be carcinogenic (cancer-causing). Animal studies had shown that extremely high doses of phenolphthalein led to tumors in animals, but it has never been shown to cause cancers in humans.
The anthranoid laxatives pass through the gastrointestinal tract unabsorbed until they reach the large intestine, where they are changed into their active forms. The resulting active compounds cause damage to the cells in the lining of the intestine and leads to apoptosis (a form of cell death). The damaged (apoptotic) cells appear as darkly pigmented bodies that may be taken up by scavenger cells known as macrophages. When enough cells have been damaged, the characteristic pigmentation of the bowel wall develops. The condition can develop after just a few months of laxative use.
How is melanosis coli diagnosed?
Melanosis coli can be observed during endoscopic procedures that examine the large intestine, such as colonoscopy and sigmoidoscopy. Sometimes the diagnosis is made upon microscopic examination of biopsies taken during endoscopic procedures.
What is the prognosis (outcome) of melanosis coli?
If a person stops using anthranoid laxatives, the changes associated with melanosis coli lessen over time and may disappear.
Early studies suggested that anthranoid laxatives might have carcinogenic or tumor-promoting activities in humans and that the presence of melanosis coli might signal an increased risk for the development of colorectal cancer. However, more recent follow-up studies have failed to show an association between colon cancer and anthranoid laxative use or between colon cancer and the finding of melanosis coli.
Latest Digestion News
Daily Health News
Health Solutions From Our Sponsors
REFERENCE: Shazia Ahmed, M.D., and Naresh T. Gunaratnam, M.D. Melanosis Coli. N Engl J Med 2003; 349:1349October 2, 2003
Top Melanosis Coli Related Articles
Abdominal Pain (Causes, Remedies, Treatment)Abdominal pain can have many causes that range from mild to severe. Some of these causes include bloating, gas, colitis, endometriosis, food poisoning, GERD, IBS (irritable bowel syndrome), ovarian cysts, abdominal adhesions, diverticulitis, Crohn's disease, ulcerative colitis, gallbladder disease, liver disease, and cancers. Signs and symptoms of the more serious causes include dehydration, bloody or black tarry stools, severe abdominal pain, pain with no urination or painful urination. Treatment for abdominal pain depends upon the cause.
Colon CancerColon cancer is a malignancy that arises from the inner lining of the colon. Most, if not all, of these cancers develop from colonic polyps. Removal of these precancerous polyps can prevent colon cancer.
Colon Cancer Prevention
Colorectal cancer is both curable and preventable if it is detected early and completely removed before the cancerous cells metastasize to other parts of the body. Colonoscopy and flexible sigmoidoscopy (along with digital rectal examination and stool occult blood testing) are both effective at preventing colo-rectal cancers and detecting early colo-rectal cancers.
Colon Cancer ScreeningColon cancer is preventable by removing precancerous colon polyps, and it is curable if early cancer is surgically removed before cancer spreads to other parts of the body. Therefore, if screening and surveillance programs were practiced universally, there would be a major reduction in the incidence and mortality of colorectal cancer.
Colon PolypsColon polyps are common growths on the inner lining of the colon. Colon polyps may become cancerous. There are several different types of colon polyps, and the chance of the polyp becoming cancerous depends on the type, size, and histology. Blood in the stool or rectal bleeding are the most common symptoms of colon polyps. Treatment for colon polyps depend on the type, size, and histology.
ColonoscopyA colonoscopy is a procedure whereby a docotor inserts a viewing tube (colonoscope) into the rectum for the purpose of inspecting the colon. Colonoscopy is the best method currently available to diagnose, detect, and treat abnormalities within the colon.
Constipation is defined medically as fewer than three stools per week and severe constipation as less than one stool per week. Constipation usually is caused by the slow movement of stool through the colon. There are many causes of constipation including medications, poor bowel habits, low fiber diets, laxative abuse, and hormonal disorders, and diseases primarily of other parts of the body that also affect the colon.
electrolyte with peg-oralPolyethylene glycol (PEG) and electrolytes are oral solutions prescribed to a patient by a health-care professional prior to colonoscopy and other examinations or procedures to cleanse the intestines, the colon (the large bowel) in particular. Side effects, drug interactions, brand names, formulations, and pregnancy and breastfeeding safety information should be reviewed prior to using this product.
Flexible SigmoidoscopyFlexible sigmoidoscopy is a procedure used to examine the lower colon and rectum. Flexible sigmoidoscopy can investigate the possible cause of
- rectal bleeding,
- bowel changes, and symptoms such as
- rectal pain,
- diarrhea, or
Laxatives For Constipation
Laxatives types for treatment of constipation include over-the-counter (OTC) preparations, for example, bulk-forming laxatives, stool softeners, lubricant laxatives, stimulant or saline laxatives, enemas, and suppositories.
Some OTC laxatives are not recommended for people with specific diseases or conditions (for example, people with diabetes). Some laxatives may have negative side effects if taken over a long time. Laxatives are not recommended for weight loss.
sennosides A&B-oral tablet
Senna (sennosides; Senokot, Senokot EXTRA, and others) is a natural medicine used to treat constipation. Side effects, drug interactions, dosage, and pregnancy safety information should be reviewed prior to taking this supplement.