Black (Dark) Stool during Pregnancy: Causes, Diagnosis & Prevention

Black (Dark) Stools During Pregnancy

Medically Reviewed By
Dr. Sabiha Anjum (Gynecologist/Obstetrician)
View more Gynecologist/Obstetrician Our Panel of Experts

Pregnancy causes great physical strain on the body, which is why most women become hyper-aware of it during the period – you’re always on the lookout for signs and symptoms of anything that seems unusual. One of these symptoms is black stools during pregnancy. This, however, can be a misleading fear since black stools alone are not dangerous. Other symptoms accompanying the stools could indicate an illness, infection, or internal bleeding. The stools alone are not an illness but an indicator or a symptom. The symptoms to watch out for when you have black stools are:

To better understand the reasons and risks associated with black stools during pregnancy, it is essential to understand the causes of black stools.

Also Read: Green Stool During Pregnancy – Is It Normal?

Causes of Black Stools During Pregnancy 

There can be numerous reasons why your body passes motions in black colour during pregnancy. Some of them are:

1. Medication

Certain types of medication can cause dark stools during your pregnancy. This is usually the first thing doctors check when examining your condition. Some variations of antacids are known to cause black stools. Over-the-counter medication is easy to access and can be harmful if taken without a prescription. It is important to remember that self-medication can be dangerous during pregnancy. Inform your doctor about the medicines you consume so that medication-related problems with your stools can be ruled out.

2. Food

It is commonly believed that dark coloured foods cause dark stools. Watch out for black or blue foods and talk to your doctor about managing your diet to balance out your nutritional intake. It is also recommended that you stay away from any food prepared using artificial food colouring during this period.

3. Iron Supplements

During pregnancy, your doctor will prescribe you iron supplements – this can cause dark coloured stools. This is absolutely normal. Most women are generally anaemic due to loss of blood during menstruation, and in the case of pregnant women, due to the increasing demand of the growing foetus. Since these supplements do not pose harm generally, continue consuming them along with iron-rich foods like spinach, meat, etc. Also, keep a check on your haemoglobin levels.

Consuming supplements during pregnancy

4. Bleeding

One of the more serious reasons for black stools during pregnancy is bleeding. It could be something as small as gastrointestinal bleeding due to extreme GERD, or something as serious as intestinal tract bleeding. Regardless of the type, it is essential to have it checked out by a doctor.

5. Health Issues

Black stools often indicate health issues. If your stool is black and has an extremely foul odour, it could be a condition called melena. If the consistency is tarry and black, it could indicate internal bleeding. If during the third term of your pregnancy the anal region swells and the stools come out black, it could be a sign of an anal tear. Talk to a doctor to understand if the black stools are related to medical issues.


Doctors can diagnose the cause of your dark stools by first taking into account the history of your physical and medical condition. If they feel the information does not point to the reason for black stools, you might have to go through a combination of x-rays, blood tests and stool examinations. This can help identify the cause of the black stool. If this is still inconclusive, then the doctor could ask you to undertake an examination called an endoscopy which involves a trained practitioner putting a tube through your oesophagus, with a camera attached to it. This tube will navigate the GI tract and try to identify the cause of the dark stool. They could also ask you to get a colonoscopy done to rule out colon infections and colon cancer as a cause.

Effective Measures to Avoid Dark Stools

Here are some effective ways to avoid dark stools during your pregnancy.

1. Increase Fibre Intake

One of the most effective ways to deal with digestive issues during pregnancy is consuming a high fibre and a mineral-rich diet that ensures your digestive system has an easy time processing and breaking down nutrients. However, this does not mean that you eliminate carbs entirely from your diet. It simply means that you increase the fibre component of your diet and consume complex and healthy carbs. Consulting a dietician and creating a meal plan that not only provides all the minerals, vitamins and nutrients your body needs but also helps enrich the efficiency of your GI tract will turn out to be beneficial. Increasing fibre content relieves constipation and prevents anal fissures or haemorrhoids, and thus, bleeding.

2. Quit Smoking

Smoking is an extremely harmful habit that not only hurts your lungs and risks cancer but also deteriorates organ health which could cause digestive tract issues, raise your blood pressure, and even cause internal bleeding. Doctors highly recommend that you quit smoking in general but especially during your pregnancy as the risks are almost three times as bad as normal and could also impact your child’s health and delivery.

3. Stay Hydrated

One of the most common reasons behind your GI tract health deteriorating is dehydration. Water plays a crucial role in maintaining a healthy digestive system as well as organ health, especially intestinal health. So, remember to drink the right amount of water and fluids during the day and consume water-rich food like watermelons, cucumbers and grapes.Pregnant woman drinking water

4. Avoid Self-medicating

Some medications can cause black stools, which is why it is recommended that you do not self-medicate during the period of your pregnancy. Before consuming any over-the-counter medication, consult a doctor and ensure that you keep them in the loop about the medication you consume.

5. Exercise

Remember that exercise is crucial for your well-being. Some light exercise will not only preserve organ health but will also help improve digestion and ensure muscle health. This is also known to help avoid black stools.

What to Do If You Notice Black Stools

Dark stools during pregnancy

It is best that you consult your doctor immediately even if the cause is minor, as it is best to rule out any danger. Remember that when you’re pregnant, you also carry the well-being of your child in your hands. Get the help of professionals whenever possible to rule out any future danger for both you and your child.

Even though black stools during pregnancy can be a mildly worrying sign, they don’t always indicate danger. Consult your doctor, follow up on the advice given, and ensure you keep an eye on the other symptoms. Communicate openly and in detail with your doctors so you take the right step forward.

Resources and References: Health Link

Also Read: 

Irritable Bowel Syndrome (IBS) during Pregnancy
Mucus in Stool While Pregnant

Previous article «
Next article »