NEJM Cases . . . The feces is a silver metastatic colorectal cancer.

Recently, the New England Journal of Medicine published an unusual case of a patient with metastatic colon cancer whose stool was silvery. The details are as follows: a 69 year old woman with metastatic colon cancer went to the emergency department for 2 weeks due to dizziness and abnormal stool color, without itching or dark urine.physical examination revealed jaundice, hepatomegaly and diffuse abdominal tenderness.rectal examination showed that the stool was silver (as shown in figure a).laboratory tests revealed hemoglobin levels of 7.5 g / dl (reference range 11.0 to 14.5), total bilirubin levels of 4.0 mg / dl (68 μ mol / L) (reference range 0.2 to 1.3 mg / dl [3 to 22 μ mol / l]), and alkaline phosphatase levels of 369 u / L (reference range 45 to 117).occult blood was positive in stool.CT scan of abdomen and pelvis revealed cecal mass and multiple liver metastases (as shown in Figure b).the appearance of silver stool is due to white stool with obstructive jaundice and black stool.after discussion with the patient, it was decided to focus on the patient's comfort.the patient received hospice care and was discharged.fecal color and characteristics can provide important diagnostic evidence for judging the functional status or pathophysiological status of digestive tract system.the reasons for the change of stool color are as follows: Brown the normal color of stool should be dark brown.bilirubin from red blood cells is broken down by bacteria in the intestine and turns it brown.human feces are usually light brown to dark brown, which is produced by a combination of bile from dead red blood cells and bilirubin derivatives of urobilin.it is usually semi-solid and has a mucus coating.Giardia lamblia infection can cause yellow feces, which can cause severe and infectious yellow diarrhea; another cause of yellow feces is Gilbert's syndrome; yellow feces can also indicate that food passes through the digestive tract relatively quickly; yellow feces can also be found in people with gastroesophageal reflux disease; yellow, greasy and smelly feces can indicate small intestine Infected.this may also be a sign of excessive fat in the feces due to impaired absorption, such as celiac disease; yellow feces may also occur if the stool is diluted or the amount of bilirubin produced by the liver is reduced.pale or gray stool may be caused by insufficient bile output, suggesting a lack of bile in the body, such as cholecystitis, gallstones, Giardia parasite infection, hepatitis, chronic pancreatitis or cirrhosis, which may indicate biliary obstruction. bile salts from the liver give the feces a brown color. if the output of bile is reduced, the color of the stool is much lighter; some drugs, such as bismuth sulfite and other anti diarrhea drugs, may also cause this discoloration. black or red black stool is usually caused by upper gastrointestinal bleeding, such as hemorrhagic peptic ulcer. black or dark brown stools may indicate upper gastrointestinal bleeding, and red stools may indicate lower gastrointestinal or rectal bleeding. the same color changes can be observed after ingestion of foods containing a large amount of animal blood; melena can also be caused by many drugs, such as bismuth salicylate and dietary iron supplements; alcoholism can also cause abnormalities in the whole body's blood pathways, including red and black feces; bright red feces often bleed in the lower intestine, often hemorrhoids, or may be red food Food coloring, beets, cranberries, tomato juice or soup, red gelatin or drinks with red food coloring can also make faeces red. Blue Prussian blue is used as a colorant for the treatment of radiation, cesium and thallium poisoning, and can make feces blue; large consumption of products containing blue food dyes, such as blue orange wine or grape soda, can have the same effect. Silver when any type of bile obstruction (white feces) is combined with gastrointestinal bleeding from any source (black feces), a discolored silver or aluminum lacquered stool color appears; it can also indicate carcinoma of the Vater's ampulla, which will lead to gastrointestinal bleeding and bile obstruction, leading to silver feces. Green feces may be due to the presence of a large amount of unprocessed bile in the alimentary tract, strong diarrhea, which makes food move too fast in the intestine, so that bile pigment can not be fully decomposed; or because some foods such as green leafy vegetables or green food are colored. some medical processes may also cause green feces. For example, bone marrow transplantation may lead to graft-versus-host disease, resulting in diarrhea and green feces; some pathogens may cause feces to turn green, including Salmonella, Giardia lamblia and norovirus. purple purple feces may have porphyria. Porphyria, also known as porphyria, is a metabolic disease caused by abnormal production and excretion of porphyrin.