Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
One
important internal process that can change the color of stool is
bleeding into
the intestines. The stool may turn black because of chemical changes to the
hemoglobin in blood caused, in part, by the action of intestinal enzymes,
particularly if bleeding is more rapid and there is a large amount of hemoglobin within the
intestines. A color change to black also is more likely if the bleeding occurs
in the upper intestine since there is more time for the chemical changes to the
hemoglobin to take place as the blood travels through the intestines.
Stool that is black
due to bleeding is also "sticky" (tarry) and smells bad. These latter
characteristics help distinguish black stools due to internal bleeding from
black stools due to the ingestion of iron or bismuth-containing medicines, for
example, bismuth subsalicylate (Pepto Bismol).
On the other hand, bleeding that occurs lower in the intestines, particularly in the colon, is likely to cause red or maroon-colored stools since there is little time for chemical changes to the hemoglobin to take place.
What other things can cause changes in the color of stool?
Another internal process that may change the color of stool but that is less
common than bleeding is pancreatic disease. The pancreas secretes enzymes into
the intestines that help with the digestion of fat, protein, and carbohydrates.
When pancreatic enzymes are not present in the intestine, fat is not fully
digested. If the content of undigested fat is high enough, stool may become a
yellowish color. The stool also appears "greasy" and smells bad. The most common
pancreatic diseases that cause this are
pancreatic tumors that block the
pancreatic duct through which the enzymes reach the intestines and chronic
pancreatitis, usually
due to damage from excessive ingestion of alcohol, that destroys the ability of the
pancreas to make enzymes. If there is both blood and undigested fat in the
stool, the stool may become silver.
Several ingested substances can change the color of stool. Iron and
bismuth-containing medications, for example, Pepto Bismol, turn the stool black. Beets and possibly some other red vegetables and fruits can turn
stool a reddish color. Food dyes used for coloring foods also may color the
stool.
Abdominal pain is pain in the belly and can be acute or chronic. Causes include inflammation, distention of an organ, and loss of the blood supply to an organ. Abdominal pain can reflect a major problem with one of the organs in the abdomen such as the appendix, gallbladder, large and small intestine, pancreas, liver, colon, duodenum, and spleen.
Rectal bleeding (hematochezia) refers to the passage of bright red blood from the anus. Rectal bleeding may be moderate to severe and most bleeding comes from the colon, rectum, or anus. Common causes include anal fissures, hemorrhoids, diverticulitis, and more.
Diarrhea is a change is the frequency and looseness of bowel movements. Cramping, abdominal pain, and the sensation of rectal urgency are all symptoms of diarrhea. Absorbents and anti-motility medications are used to treat diarrhea.
Gallstones are stones that form when substances in the bile harden. Gallstones (formed in the gallbladder) can be as small as a grain of sand or as large as a golf ball. There can be just one large stone, hundreds of tiny stones, or any combination. The majority of gallstones do not cause symptoms.
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, abuse of laxatives, hormonal disorders, and diseases primarily of other parts of the body that also affect the colon.
Blood clots can occur in the venous and arterial vascular system. Blood clots can form in the heart, legs, arteries, veins, bladder, urinary tract and uterus. Risk factors for blood clots include high blood pressure and cholesterol, diabetes, smoking, and family history. Symptoms of a blood clot depend on the location of the clot. Some blood clots are a medical emergency. Blood clots are treated depending upon the cause of the clot. Blood clots can be prevented by lowering the risk factors for developing blood clots.
Pancreatic cancer is a malignant tumor of the pancreas. Pancreatic cancer has been called a "silent" disease because early pancreatic cancer usually does not cause symptoms.
Anal itching is the irritation of the skin at the exit of the rectum, known as the anus, accompanied by the desire to scratch. Causes include everything from irritating foods we eat, to certain disease and infections. Treatment options include local anesthetics, vasoconstrictors, protectants, astringents, antiseptics, keratolytics, analgesics, and corticosteroids. If condition persists, a doctor examination may be needed to identify an underlying cause.
Clostridium difficile (C. difficile) is a bacterium, and is one of the most common causes of infection of the colon. C. difficile spores are found frequently in hospitals, nursing homes, extended care facilities, and nurseries for newborn infants. They can be found on bedpans, furniture, toilet seats, linens, telephones, stethoscopes, fingernails, rings, floors, infants' rooms, and diaper pails. They even can be carried by pets. Antibiotic-associated (C. difficile) colitis is an infection of the colon caused by C. difficile that occurs primarily among individuals who have been using antibiotics. Treatment for C. difficile colitis hydration, replenishment of electrolyte deficiencies, discontinuing the antibiotic that caused the colitis, and using antibiotics to eradicate the C. difficile bacterium.
Pancreatitis is a rare disease in which the pancreas becomes inflamed, occurring when digestive enzymes are activated and begin attacking the pancreas causing damage to the gland. There are two types of pancreatitis, acute and chronic. Most commonly caused by alcohol or gallstones, it can lead to bleeding in the gland, serious tissue damage, infection, and cysts. Enzymes and toxins may then enter the bloodstream and seriously injure organs, such as the heart, lungs, and kidney.
Celiac disease is a result of an immune reaction to gluten, a protein found in wheat or related grains and present in many foods that we eat. Celiac disease causes impaired absorption and digestion of nutrients through the small intestine. Signs and symptoms of celiac disease include malabsorbption (diarrhea, foul smelling gas, bloating, and increased amounts of fat in the stool) and malnutrition (weight loss, edema, anemia, bruising easily, neuropathy, and infertility). Treatment for celiac disease is a gluten free diet, and at times if necessary, medications
Internal bleeding occurs when an artery or vein is damaged and blood to escapes the circulatory system and collects inside the body. Internal bleeding can be caused by a variety of situations such as blunt trauma, deceleration trauma, medications, fractures, and spontaneous bleeding. Treatment of internal bleeding depends on the cause of the bleeding.
Inflammation of the inner lining of the colon is referred to as colitis. Symptoms of the inflammation of the colon lining include diarrhea, pain, and blood in the stool. There are several causes of colitis including infection, ischemia of the colon, inflammatory bowel disease (Crohn's disease, Ulcerative colitis, or microscopic colitis). Treatment depends on the cause of the colitis.
Cystic fibrosis is a disease of the mucus and sweat glands. Cystic fibrosis is an inherited disease. The outcome of the disease leaves the body malnourished, bulky and fouls smelling stools, vitamin insufficiency, gas, painful or swollen abdomen, infertility, susceptible to heat emergencies, and respiratory failure. There is no cure for cystic fibrosis, treatment of symptoms is used to manage the disease.
Gastritis is an inflammation of the stomach lining. Causes of gastritis include drinking too much alcohol, medications such as NSAIDs, ibuprofen, aspirin, H. pylori infection, severe infections, burns, anemia, and autoimmune disorders. Gastritis is diagnosed with endoscopy, blood tests, or stool tests. Treatment depends upon the cause of gastritis.
Barrett's esophagus occurs as a complication of chronic gastroesophageal reflux disease (GERD), primarily in white males. GERD refers to the reflux of acidic fluid from the stomach into the esophagus (the swallowing tube), and is classically associated with heartburn.
Pancreatic cysts are collections of fluid within the pancreas. Some are benign, malignant, or pseudocysts. There are two major types of pancreatic cysts, inflammatory cysts and non-inflammatory cysts. Non-inflammatory cysts include: serous cyst adenomas, mucinous cyst adenomas, intraductal papillary mucinous neoplasm (IPMN), and solid pseudopapillary tumor of the pancreas. Symptoms of pancreatic cysts include abdominal pain, jaundice, fever, chills, and sepsis. Treatment depends on the type of cyst, and patient health.
Intussusception is the telescoping (prolapse) of a portion of the intestine within another immediately adjacent portion of intestine. Intussusception affects children between the ages of 3 months and 6 years of age. The causes of intussusception is not clearly understood. Symptoms of intussusception include bilious vomiting, "currant jelly stool," and colicky abdominal pain. Intussusception is an emergency requires immediate attention.
Digestion is the complex process of turning food you eat into the energy you need to survive. The digestive process also involves creating waste to be eliminated, and is made of a series of muscles that coordinate the movement of food.
Nonsteroidal antiinflammatory drugs (NSAIDs) are prescribed medications for the treatment of inflammatory conditions. Examples of NSAIDs include aspirin, ibuprofen, naproxen, and more. One common side effect of NSAIDs is peptic ulcer (ulcers of the esophagus, stomach, or duodenum). Side effects, drug interactions, warnings and precautions, and patient safety information should be reviewed prior to taking NSAIDs.
Hemophilia is one of a group of inherited bleeding disorders. Hemophilia A and B are inherited in an X-linked recessive genetic pattern and is more common in males. Symptoms of hemophilia include bleeding into the joints, muscles, GI or urinary tract, or brain or skull. Treatments for hemophilia is generally replacement of blood clotting factors.
Hepatitis means inflammation of the liver. Hepatitis A is one type of liver disease caused by a virus. Since hepatitis A is a virus, it can pass from person to person from eating or drinking contaminated food or coming into contact with contaminated materials containing the virus. Symptoms of hepatitis A include stomach pain, diarrhea, dark yellow urine, jaundice, and more. There is a vaccine to prevent contracting hepatitis A.
Idiopathic means that the cause of the condition isn't known. Thrombocytopenic means there's a lower than normal number of platelets in the blood. Purpura refers to purple bruises caused by bleeding under the skin. Idiopathic thrombocytopenic purpura (ITP) is a bleeding condition in which the blood doesn't clot as it should. This is due to a low number of blood cell fragments called platelets.
Irritable bowel syndrome (IBS) in children is a functional gastrointestinal disorder with symptoms of abdominal pain, bloating, diarrhea or constipation. The cause of IBS is unknown, however, certain foods, stress, anxiety, and depression may contribute to the symptoms of IBS. There is no cure for IBS in children; however, medications, dietary changes, and stress management may relieve symptoms.
Enterovirulent Escherichia coli (E. coli) are strains of related bacteria that have a strong propensity to cause gastrointestinal tract infections. Examples of strains include: EHEC (enterohemorrhagic E. coli), ETEC (enterotoxigenic E. coli), EPEC (enteropathogenic E. coli), EIEC (enteroinvasive E. coli), EAEC (enteroadherent E. coli), and EAggEC (enteroaggregative E. coli). Symptoms may vary depending on the strain the individual contracts. Infection is spread generally through contaminated food or drink.