Top 4 Causes of Dark Brown Stool
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When it comes to poop colors, there are different shades of normal. Looking at your bowel movements can help you understand what’s normal for you and when there may be a problem.
Stool that appears blackish or reddish in color can be a concern. It can indicate blood in the stool and may be a more serious gastrointestinal tract issue.
But stool that simply seems darker than normal may be the result of dehydration, constipation, or eating dark-colored foods or iron-rich foods or supplements. In some cases, it may be caused by digestive conditions such as irritable bowel syndrome (IBS).
1. Food and medications
Many foods or medications may naturally cause your stool to change colors, including looking dark brown or black. Common foods known to do this include licorice, blueberries, beets, red-colored gelatin or food made with blood (ie blood sausage). Common medications known to do this include iron supplements and/or medications with bismuth including Pepto-Bismol and Kaopectate. —Dr. Chandra Manuelpillai
- Dark brown stool
Many foods or medications may naturally cause your stool to change colors, including dark brown or black. Common foods known to do this include licorice, blueberries, beets, anything with food coloring, and food made with blood (i.e., blood sausage).
Iron supplements and medications with bismuth, such as Pepto-Bismol and Kaopectate, can also change stool color.
- Difficulty emptying your bowels or feeling “blocked”
- Having fewer than three bowel movements in a week
- Hard, pellet-like stool
- Abdominal cramping
Constipation can be due to a host of factors, including poor diet, dehydration, being inactive, hormone fluctuations, and a side effect of medication.
In general, constipation can be avoided by eating a fiber-rich diet, increasing water intake, and exercising regularly.
Medications can also cause constipation. If you recently started a new medication, check with your doctor if you get constipated. They may suggest taking the medication at a certain time of day or with certain foods.
Menstruating women may have constipation prior to their period, due to hormone fluctuations. Pregnant women may also get constipation due to the hormonal changes.
Laxatives may be used to treat constipation. However, even over-the-counter (OTC) laxatives can have side effects. Some may also interfere with your body’s ability to absorb other medications you’re taking.
Overuse or prolonged use of laxatives can cause decreased bowel function, like your bowel’s natural ability to contract. This can lead to dependence on them.
If you need to use a laxative on a regular basis, talk with your doctor. Women who are pregnant and children less than 6 years old should not take a laxative without first discussing it with a doctor.
Some people also may experience what’s known as chronic constipation. If constipation does not go away despite making dietary changes, such as increasing fiber intake, see a doctor.
3. Irritable bowel syndrome
- Abdominal cramps
- Diarrhea or constipation
- Bloating and/or abdominal discomfort
Irritable bowel syndromes (IBS) is a chronic disorder of the colon (large intestine) that can flare up at different times. There is no definitive cause of IBS, but it could be caused by abnormal muscle movements in the gut. It may also be affected by your nervous system.
Sometimes flare-ups are due to stress, diet, or other changes. IBS can have different symptoms depending on the person, but most experience abdominal cramps or discomfort.
IBS may affect the color and consistency of your stool. You may feel constipated or you may have trouble reaching the bathroom. IBS symptoms can last a long time. If you notice a change in stool color accompanied by abdominal pain or a change in your bowel habits, see a doctor.
4. Gastrointestinal bleed
- Upper abdominal (burning) pain that gets worse after eating
- Lower abdominal cramping
- Black/brown (coffee ground) or bright, red blood vomit
- Black/tarry or bright, red stool
- Shortness of breath
If your stool is a darker color than normal, it may indicate internal bleeding. You can have both upper and lower gastrointestinal (GI) bleeds.
Upper GI bleeds tend to be from gastritis (inflammation of the stomach lining) or ulcers but there are other causes as well. These usually start off slow and may have no symptoms other than belly pain when eating.
The slow bleed may eventually cause anemia, which causes fatigue, shortness of breath, and dizziness. Once the blood goes through the digestive system, it turns the stool a darker brown and eventually looks black or tarry.
Lower GI bleeds tend to be bright red, bloody stools because there’s not enough time for the blood to be digested to turn the stool a darker brown, black, or tarry. The most common causes of lower GI bleeds are diverticular disease and hemorrhoids. Sometimes hemorrhoids will cause blood-streaked stool, because the blood gets on the stool as it passes.
It is important to discuss bleeding with your doctor as soon as possible. Slower bleeds are less serious, but you should go directly to an emergency department if you are vomiting or have bright red stool, experience symptoms of anemia, or develop any worrying symptoms like chest pain. This can be life threatening.
Dark brown stool in children
Dark brown stool in children should be monitored.
Constipation in children is often due to not getting enough fiber-rich fruits and vegetables, dehydration, and/or behavioral factors, such as a desire for control or holding stool out of fear of using the toilet or not wanting to stop playing. This can be a problem in young children, especially those who were toilet trained recently.
Children often complain of abdominal pain or pain when trying to pass a stool. The best treatment is prevention. Provide a high-fiber diet and lots of water and other liquids. It can also help to encourage a bathroom routine.
If your child still has trouble with passing a stool or complains about pain while using the toilet, see a doctor. Never start a new medication, even an over-the-counter medication, without first discussing this with your child’s pediatrician. This is particularly true with laxatives. Sometimes constipation is due to an underlying problem that should be addressed first.
When to call the doctor
Don’t feel uncomfortable talking about your stool with your doctor. “Everyone poops.” —Dr. Manuelpillai
Most cases of dark brown stool can be managed with your doctor. It is fine to try increasing fluid intake if you think it is from dehydration. If you think it is from constipation, you can try increasing fiber, fluids, and/or exercise before contacting your physician.
If these approaches don’t work or if you are concerned about other possible causes, such as IBS, GI bleeding, or cancer, discuss it with your doctor.
Should I go to the ER for dark brown stool?
You should go to the ER if your dark brown stool is accompanied by these symptoms:
- Severe abdominal pain/cramping with or without vomiting or being unable to eat or drink.
- Brown, black, or bright red vomit or stool, which could indicate internal bleeding.
- Symptoms of anemia, including dizziness, fatigue, shortness of breath, heart palpitations, and/or chest pain.
Treatment for dark brown stool
The appearance of stool—color, consistency, shape, etc.—can tell you a lot about your health including diet, dehydration, medical problems (i.e. gastrointestinal bleed, malabsorption, liver failure, infections, malignancy, etc.). It is important to monitor your stool regularly. —Dr. Manuelpillai
- Drink more water.
- Include more fiber-rich foods in your diet.
- Increase physical activity/exercise.
- Monitor other symptoms, such as abdominal pain, or whether stool consistency and color stay the same after changing your diet.
Other treatment options
- Medications (whether over-the-counter or prescribed) after discussing with your doctor.
- IV-fluid infusions.
- Tests to determine the cause of a GI bleed or to diagnose IBS.
Dr. Manuelpillai is a board-certified Emergency Medicine physician. She received her undergraduate degree in Health Science Studies from Quinnipiac University (2002). She then went on to graduated from Rosalind Franklin University of Medicine and Sciences/The Chicago Medical School (2007) where she served on the Executive Student Council, as well as was the alternate delegate to the AMA/ISMS-MSS Governing Council and the student representative to the Illinois State Medical Society (ISMS) Education and Health Workforce committee. She completed an internship year with UCLA-Harbor Medical Center's Department of Internal Medicine followed by an emergency medicine residency program at Boston Medical Center (2011) while also serving as the resident representative to the Massachusetts Medical Society (MMS) committee on Student Health & Sports Medicine. She then started working at Saints Medical Center (later Lowell General Hospital/Saints Campus and Main Campus) in Lowell Massachusetts where she served as the Continuous Quality Improvement Director for the emergency medicine group, as well as was the representative for the emergency department on the Sepsis, Stroke and PCI Quality Assurance and Compliance Committees. She joined Buoy Health in 2019. She currently works in multiple emergency departments both in the community and academics, as well as previously worked in multiple urgent care centers. She believes this mix of experiences has given her a unique perspective on the care of acute illnesses.