Serious illnesses are often accompanied by warning signs or symptoms that not only indicate the body’s response to disease but also serve as an alert to take action.
These early warning signs suggest that the body is under threat and requires prompt attention to eliminate potential hazards. For example, the sudden appearance of black stools is an unusual sign that requires immediate investigation.
Bowel movement is a natural biological process, and many diseases can be revealed through the examination of stool. Traditional Chinese medicine (TCM) practitioners often ask about their patients’ bowel movements during diagnosis, as the color, form, and odor of the stool can provide insight into their overall health.
Generally, the healthy stool is brown, soft, and solid. If there is a sudden change in bowel movement, it is important to investigate the underlying cause as such changes may indicate an internal problem in the body.
Black Stool Is a Commonly Overlooked Symptom of Upper Gastrointestinal Bleeding
Many people tend to focus only on surface-level symptoms and become fixated on treating them while overlooking the life-threatening illness hidden behind them.One day, I received a call from a woman in London who told me that her husband, Mr. Lin, had fainted while using the bathroom at around five in the morning. When he woke up, he found that two of his front teeth had been damaged and his lips were cut, resulting in a significant amount of bleeding. They were very concerned about the damage to his teeth and the bleeding, so they promptly went to see a dentist.
However, due to the pandemic, the dental clinic was going to close the next day, so they could not extract the teeth as the dentist had suggested. So, the woman asked me if there were any alternatives to tooth extraction. Could his teeth heal on their own over time, or could traditional Chinese medicine be used to treat them?
The patient’s family was concerned about the patient’s teeth—but as a traditional Chinese medicine practitioner—should we first follow the patient’s family’s line of thought and try to address the teeth problem, or should we first investigate the cause of the fainting?
Clearly, the latter is of greater importance since the fainting may have been caused by a life-threatening factor. If we focus solely on treating the surface-level symptoms and fail to rule out the underlying issue, we may risk delaying proper diagnosis and treatment, ultimately putting the patient’s life in jeopardy.
Fainting can be caused by many factors. What could have caused Lin’s fainting? Does he have any pre-existing medical conditions? Has he experienced any discomfort lately? According to Mrs. Lin, her husband does not have any chronic illnesses, but he has been having some gastrointestinal issues in recent months.
Three days prior to fainting, Lin had diarrhea after eating chocolate cake and has been having two to three bowel movements a day since then. Additionally, the stool appeared black in color, which led the couple to suspect that the chocolate cake was not properly digested.
Upon learning that Lin had been passing black stools for three days, I was shocked and immediately suspected that he may have been suffering from upper gastrointestinal bleeding. I could not help but wonder if the excessive bleeding had led to a transient ischemic attack, which could have caused him to faint.
So, I asked Mrs. Lin how her husband fainted and how long he had remained unconscious. She replied that she did not know how he fainted, but she was aware of the duration of his loss of consciousness because she knew what time he went to the bathroom.
Then, I spoke directly with Lin and asked him what happened during his fainting episode and whether he had experienced any symptoms beforehand, such as sudden headaches or dizziness. Lin replied, “I have absolutely no recollection of what happened before I fainted, and I do not know how I fainted.”
This ruled out the possibility that he had accidentally bumped into something and fainted. It was highly likely that he fainted due to upper gastrointestinal bleeding, which led to cerebral ischemia that could have caused instant memory loss.
When I spoke with Lin, his voice was weak and feeble, and it was clear that he was in a frail state. I inquired about any discomfort or illnesses he had been experiencing, and he shared that he had been passing black stools on and off for the past three months.
In addition to the fainting episode, stomach discomfort, diarrhea, and multiple stools, his appetite had not been great for the past few months, and he sometimes felt bloated after eating, though there was no pain.
During our video call, I observed Lin’s tongue and noticed that it was pale with a white and slightly thick coating, indicating weak spleen and stomach function, which was consistent with his other symptoms.
To further confirm that the black stools were caused by upper gastrointestinal bleeding, I asked Mrs. Lin to send me a photo of her husband’s stool after he had a bowel movement. However, she felt embarrassed and only sent me a picture of toilet paper with a small amount of fecal matter on it, which was completely black.
When I saw the photo, I was shocked because there was no way that the black color could have been caused by food. No food could possibly turn fecal matter into such a terrifying shade of black! (Attached is a photo of the black stools—you won’t believe the color!)

How Much Blood Has to Be Lost From the Digestive Tract for the Stool to Turn Black?
Black stools are typically caused by bleeding in the upper gastrointestinal tract. When blood remains in the intestines for an extended period, red blood cells break down and hemoglobin reacts with sulfides to form ferrous sulfide, resulting in black-colored stools. Modern medicine has found that black stools may only occur when a patient loses more than 50 milliliters (0.05 liters) of blood per day.Assuming Lin experienced black stools on a daily basis would indicate that he was losing at least 50 milliliters (0.05 liters) of blood per day. Over a period of three consecutive months, this would result in a total blood loss of at least 4,500 milliliters (4.5 liters). Even if Lin had only experienced black stools half of the time, he would still have lost at least 2,250 milliliters (2.25 liters) of blood.
Based on Lin’s weight at the time, 60 kilograms (132.27 pounds), his estimated total blood volume was 4,800 milliliters (4.8 liters). When blood loss exceeds 1,500 milliliters (1.5 liters), it can cause insufficient blood supply to the brain, dizziness, and even loss of consciousness. When blood loss reaches 2,000 milliliters (2 liters) or more, it can be life-threatening.
Although Lin’s total blood loss over those three months had exceeded the body’s limit, he had not been in immediate danger due to the chronic nature of his bleeding. The human body has compensatory mechanisms that increase blood production to compensate for blood loss.
However, the rate of blood production was unable to keep up with the rate of Lin’s chronic blood loss, resulting in a gradual decrease in total blood volume and eventually leading to fainting. In other words, the fainting episode indicated that his blood loss had reached its maximum capacity, and if the bleeding persisted, it could have become life-threatening.
Under the circumstances of chronic blood loss and extreme weakness, having the damaged teeth extracted would only have worsened the situation. Fortunately, the dental clinic was closed.
Due to the increasingly specialized nature of modern medicine, each specialty only focuses on diseases within its own domain and often has little to no understanding of other specialties. This can be detrimental to patient care, as the human body is a complex system and it is unlikely for a patient to have only one illness. In cases where a patient is afflicted by several illnesses, it can be difficult to determine which specialist to consult.
What Is Considered ‘Normal’ Black Stool and How to Differentiate It?
As mentioned above normal stools are typically brown, soft, and well-formed. So, how can we tell which types of black stool are normal?1. Foods With High Iron Content Can Lead to Black Stool
The color of our stool is closely related to the food we eat. If we consume food with darker colors, our stool will be darker as well. Foods that are high in iron, such as spinach and pig blood curd (also known as “blood tofu” or “blood pudding”—a popular Cantonese delicacy in Asian countries), can also cause black stool. However, once we stop eating these foods, the color of our stool will return to normal.2. Some Chinese Herbal Medicines Can Cause Black Stool
Lin should have asked advice from his traditional Chinese medicine practitioner if he was taking any Chinese herbal medicine. In fact, TCM practitioners typically inquire about the condition of the stool during diagnosis and will promptly address any issues. Certain medicinal herbs, such as dang gui, he shou wu, shu di, xue yu tan, and jing jie tan, may cause the stool to become darker in color.3. Certain Western Medicine Can Also Cause Black Stool
Iron supplements and medications containing bismuth (the main ingredient in Pepto-Bismol) can also cause black stool. It would be best to consult with the prescribing doctor for more information.Emergency Treatment
Lin’s condition had reached a critical point and required urgent treatment to stop the bleeding and improve his overall health. However, at that time, during the peak of the pandemic, many people were unable to reach an ambulance or were hesitant to go to the hospital due to fear of infection. If they developed a fever, hospitals would ask them to self-isolate at home, making it impossible to seek medical attention.Therefore, I explained Lin’s condition to his family and suggested that they come to my clinic to pick up some Chinese medicine that night. Unfortunately, due to the long distance and other factors, they were unable to make it.
The next day, Lin’s condition had worsened, but fortunately, his family was able to contact an ambulance and he was taken to the hospital for treatment. At the hospital, a CT scan and an endoscopic examination were performed, revealing that Lin was suffering from gastritis, duodenal ulcer, and upper gastrointestinal bleeding (which was located at the site of the duodenal ulcer).
Due to the significant amount of bleeding, Lin received two units of blood transfusion, along with medication, and was kept under observation at the hospital for a night. He was discharged the following day.
After the emergency treatment at the hospital, the upper gastrointestinal bleeding stopped. However, the gastritis and duodenal ulcer remained untreated and were difficult to cure with Western medicine.
How Does Traditional Chinese Medicine Treat Black Stool?
Some people hold the view that traditional Chinese medicine is slow to take effect and liken it to a “slow doctor.” However, this perspective is incomplete, as TCM emphasizes gradual treatment of the root causes of an illness while urgently addressing its symptoms.Nowadays, most individuals who turn to TCM treatment have already tried Western medical treatment without success, leading to the progression of acute illnesses into chronic ones. In such cases, TCM practitioners can only focus on addressing the underlying cause of the disease and treating its complex nature meticulously and patiently.
However, for patients who are experiencing bleeding, this symptom is considered an emergency, and stopping the bleeding is the top priority. The approach to stopping bleeding in TCM differs from that in Western medicine, as TCM also considers the patient’s overall physiological function, ensuring that after the bleeding is stopped, blood stasis does not remain in the body, and organs can function properly while generating new blood to replenish the lost blood.
Therefore, TCM treatment for black stool includes hemostatic function, prevention of blood stasis in the body, and enhancement of the digestive and absorptive functions of the spleen and stomach. This enables the body to absorb more essential nutrients and convert them into blood, helping to alleviate the patient’s symptoms and improve their overall health.
In ancient China, a miraculous hemostatic herbal recipe called “Huangtu Tang” was discovered, which has proven to be highly effective in treating upper gastrointestinal bleeding. TCM has been using Huangtu Tang for at least 2,000 years, and it was recorded in the “Essential Prescriptions from the Golden Cabinet” by the Han dynasty medical sage, Zhang Zhongjing.
Huangtu Tang not only stops upper gastrointestinal bleeding, but also tonifies the spleen and stomach, nourishes the intestines, and promotes blood circulation to dispel stasis, thereby gradually restoring the healthy function of the digestive system. It is a widely regarded formula for treating the underlying causes of upper gastrointestinal bleeding.
The ingredients of Huangtu Tang include zao zhong huang tu, gan di huang, e jiao, fu zi, bai zhu, gan cao, and huang qin.
However, due to the changes in time, differences in climate and environment, and variations in individual physical conditions, we cannot blindly apply ancient prescriptions to modern-day treatment. Considering Lin’s specific situation, we have made the following adjustments to the original formula:
Zao zhong huang tu (25g), huang qi (9g), dang shen (9g), shu di huang (6g), e jiao (6g), bai zhu (6g), rou gui (3g), gan jiang (3g), bai zhu (3g), bai shao (3g), huang qin (6g), and gan cao (3g).
Emergency Bleeding Control Using Traditional Methods
In certain urgent situations, it may be difficult to reach a traditional Chinese medicine practitioner or a Western doctor or to acquire all the necessary Chinese herbs mentioned above. In such cases, is it possible for us to manage the emergency situation and stop the bleeding as quickly as possible? Below, we present some traditional methods for emergency bleeding control that can be employed as a last resort.1. Stop Bleeding Using Xue Yu Tan (Carbonized Hair)
The most potent Chinese herbal medicine for stopping bleeding is carbonized hair, also known as xue yu tan. Xue yu refers to human hair, and xueyu tan is the ash obtained by burning hair. Ancient people believed that human hair is derived from blood and contains components that can stop bleeding. When burned into ash, it has a remarkable effect on stopping bleeding.In times of crisis, contributing one’s hair to save a life is something that many people are willing to do. The use of carbonized hair for stopping bleeding in China dates back at least 2,000 years, and it is recorded in one of the earliest Chinese pharmacological classic, “The Divine Farmer’s Classic of Materia Medica.”
2. Stop Bleeding Using Juan Bai Tan (Carbonized Chinese Arborvitae)
Chinese arborvitae, also known as juan bai, is a common ornamental plant found in many households. However, many people are unaware that it is an excellent hemostatic agent that can stop bleeding without leaving blood stasis in the body.Recipes for Nourishing the Body
1. Codonopsis and Lotus Root Chicken Soup
Ingredients: 1 whole hen, lotus root (500g), astragalus, and codonopsis (15g each), bai zhu (9g), shu di, and dried tangerine peel (6g each).2. Lotus Root Starch and Egg Custard
Ingredients: 1 egg, lotus root starch (30g), qian shi (5g), Chinese yam (5g), and sanqi powder (1g).You can add an appropriate amount of brown sugar or salt according to personal preference. Consume once a day.
*Some herbs mentioned in this article may be unfamiliar, but they are generally available in Asian supermarkets.