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Stomach upset is a common problem, and many people will take an over-the-counter remedy to get some relief. Some of the different medicines that can be used for stomach problems includePepto-Bismolor Kaopectate.
Feeling better typically happens pretty quickly, but later that day or the day after, something really weird happens in the bathroom. The next bowel movement or two show a difference and it could beblack stoolor maybe even green stool.
How Bismuth Subsalicylate Works
Pepto-Bismol and Kaopectate (which are two of the well-known brand names, there are also generics or store brands that have similar ingredients) can be found over-the-counter in drug stores.
These medications are often used for an upset stomach, such as after eating too much food, or for mild stomach discomfort from a variety of causes. They’re not usually the type of drugs that are prescribed for chronic conditions or ongoing digestive complaints because they may not be effective at treating more serious problems.
People who find themselves taking over-the-counter medications to manage digestive upset for longer than a few days, or who need them several times a month, should contact a physician.
Bismuth subsalicylate is anantidiarrheal drug. In the digestive system it calms inflammation and reduces the amount of water entering the bowel. This can slow down the production of loose stools or diarrhea. It also has antibacterial properties and may inhibit organisms that cause diarrhea and other gastrointestinal symptoms.
A small amount of a substance called sulfur is present both in saliva and in the gastrointestinal tract. Sulfur interacts with bismuth, theactive ingredientthat’s used in Pepto-Bismol. The result is a new substance called bismuth sulfide, which is what causes the stool to turn black.
Stool Color Concerns
The black or green stool after taking bismuth subsalicylate can last for several days, but it is harmless. Thischange in stool coloris not a cause for concern unless you have stopped taking the bismuth subsalicylate and the changes in the stool color persist.
If the black or green color in your stool does not go away a few days after the medicine is stopped, there could be something else going on that’s causing the changes.
Black Stool
Black stoolcan happen for a variety of other reasons, including taking iron supplements and eating certain black, green, or purple foods (like black sandwich cookies). But when it can not be traced to a food or a supplement, a doctor should be consulted because black stools or stools that appear tarry could actually contain blood.
Green Stool
Green stoolis also common, especially after eating green or purple foods, However, green stool that continues for a long time could actually be because of a medical problem.
When stool moves through the body too quickly, it doesn’t get a chance to be changed to brown, and it stays green. That’s why when green stools and diarrhea occur together, it should be discussed with a doctor.
Causes of Green Diarrhea
A Word From Verywell
Even if it’s pretty likely that a stool has changed color because of the bismuth subsalicylate in Pepto Bismol, having these other symptoms is still a reason to contact a physician to make sure there’s not a serious condition causing them.
Frequently Asked QuestionsIt can be, especially if it has a foul smell and if you haven’t recently consumed dark foods, iron supplements, or stomach upset medicine. Black, tarry stool may indicate that you have bleeding in the stomach, small intestine, or colon.See your healthcare provider for an exam and diagnosis.Learn MoreWhat Causes Green Poop?While it may seem very strange, black stool is not something to worry about.You can continue taking Pepto-Bismol if needed, and the changes in your stool should go away when you stop.Learn MoreWhat You Need to Know About Treating DiarrheaYes. Water can help you recover from diarrhea, which dehydrates you, and it can relieve nausea. You can also opt for herbal teas that are safe for pregnant women.Learn MoreWhat Is Nausea?
Frequently Asked Questions
It can be, especially if it has a foul smell and if you haven’t recently consumed dark foods, iron supplements, or stomach upset medicine. Black, tarry stool may indicate that you have bleeding in the stomach, small intestine, or colon.See your healthcare provider for an exam and diagnosis.Learn MoreWhat Causes Green Poop?
It can be, especially if it has a foul smell and if you haven’t recently consumed dark foods, iron supplements, or stomach upset medicine. Black, tarry stool may indicate that you have bleeding in the stomach, small intestine, or colon.See your healthcare provider for an exam and diagnosis.
Learn MoreWhat Causes Green Poop?
While it may seem very strange, black stool is not something to worry about.You can continue taking Pepto-Bismol if needed, and the changes in your stool should go away when you stop.Learn MoreWhat You Need to Know About Treating Diarrhea
While it may seem very strange, black stool is not something to worry about.You can continue taking Pepto-Bismol if needed, and the changes in your stool should go away when you stop.
Learn MoreWhat You Need to Know About Treating Diarrhea
Yes. Water can help you recover from diarrhea, which dehydrates you, and it can relieve nausea. You can also opt for herbal teas that are safe for pregnant women.Learn MoreWhat Is Nausea?
Yes. Water can help you recover from diarrhea, which dehydrates you, and it can relieve nausea. You can also opt for herbal teas that are safe for pregnant women.
Learn MoreWhat Is Nausea?
5 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Switaj TL, Winter KJ, Christensen SR.Diagnosis and management of foodborne illness.Am Fam Physician.2015 Sep 1;92(5):358-365.Keogan DM, Griffith DM.Current and potential applications of bismuth-based drugs.Molecules. 2014;19(9):15258-97. doi:10.3390/molecules190915258Kamboj AK, Hoversten P, Leggett CL.Upper gastrointestinal bleeding: etiologies and management.Mayo Clin Proc. 2019;94(4):697-703. doi:10.1016/j.mayocp.2019.01.022MedlinePlus.Black or tarry stools.MedlinePlus.Bismuth subsalicylate.Additional ReadingPitz AM, Park GW, Lee D, Boissy YL, Vinjé J.Antimicrobial activity of bismuth subsalicylate on Clostridium difficile, Escherichia coli O157:H7, norovirus, and other common enteric pathogens.Gut Microbes. 2015;6:93-100. doi:10.1080/19490976.2015.1008336.
5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Switaj TL, Winter KJ, Christensen SR.Diagnosis and management of foodborne illness.Am Fam Physician.2015 Sep 1;92(5):358-365.Keogan DM, Griffith DM.Current and potential applications of bismuth-based drugs.Molecules. 2014;19(9):15258-97. doi:10.3390/molecules190915258Kamboj AK, Hoversten P, Leggett CL.Upper gastrointestinal bleeding: etiologies and management.Mayo Clin Proc. 2019;94(4):697-703. doi:10.1016/j.mayocp.2019.01.022MedlinePlus.Black or tarry stools.MedlinePlus.Bismuth subsalicylate.Additional ReadingPitz AM, Park GW, Lee D, Boissy YL, Vinjé J.Antimicrobial activity of bismuth subsalicylate on Clostridium difficile, Escherichia coli O157:H7, norovirus, and other common enteric pathogens.Gut Microbes. 2015;6:93-100. doi:10.1080/19490976.2015.1008336.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Switaj TL, Winter KJ, Christensen SR.Diagnosis and management of foodborne illness.Am Fam Physician.2015 Sep 1;92(5):358-365.Keogan DM, Griffith DM.Current and potential applications of bismuth-based drugs.Molecules. 2014;19(9):15258-97. doi:10.3390/molecules190915258Kamboj AK, Hoversten P, Leggett CL.Upper gastrointestinal bleeding: etiologies and management.Mayo Clin Proc. 2019;94(4):697-703. doi:10.1016/j.mayocp.2019.01.022MedlinePlus.Black or tarry stools.MedlinePlus.Bismuth subsalicylate.
Switaj TL, Winter KJ, Christensen SR.Diagnosis and management of foodborne illness.Am Fam Physician.2015 Sep 1;92(5):358-365.
Keogan DM, Griffith DM.Current and potential applications of bismuth-based drugs.Molecules. 2014;19(9):15258-97. doi:10.3390/molecules190915258
Kamboj AK, Hoversten P, Leggett CL.Upper gastrointestinal bleeding: etiologies and management.Mayo Clin Proc. 2019;94(4):697-703. doi:10.1016/j.mayocp.2019.01.022
MedlinePlus.Black or tarry stools.
MedlinePlus.Bismuth subsalicylate.
Pitz AM, Park GW, Lee D, Boissy YL, Vinjé J.Antimicrobial activity of bismuth subsalicylate on Clostridium difficile, Escherichia coli O157:H7, norovirus, and other common enteric pathogens.Gut Microbes. 2015;6:93-100. doi:10.1080/19490976.2015.1008336.
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