Introduction
The discoloration of diarrhea can look different and can be due to a variety of causes. Often the discoloration is caused by the diet, i.e. the intake of certain foods or dietary supplements. In addition, bleeding of the stomach or small intestinal mucosa can also cause the stool to turn black and cause diarrhoea. For this reason, prolonged and recurring complaints with black diarrhea should be clarified.
The causes of black diarrhea
Overdosage of iron tablets Consumption of iron-containing food (spinach…) Consumption of dark-colored food (red wine, beetroot…) Bleeding from the mucous membrane of the upper gastrointestinal tract: Consumption of dark food coloring Endometriosis (tissue of the uterine lining located in the intestine, which builds up and breaks down with the menstrual cycle)
- The overdose of iron tablets
- The consumption of ferrous foods (spinach …)
- The consumption of dark colored food (red wine, beetroot…)
- Bleeding at the mucous membrane of the upper gastrointestinal tract: esophagus stomach duodenum
- Oesophagus
- Stomach
- Duodenum
- The consumption of dark food coloring
- Endometriosis (tissue of the uterine mucosa located in the intestine, for example, which builds up and breaks down with the menstrual cycle)
- Oesophagus
- Stomach
- Duodenum
The molecular components of food colouring are mostly not utilized and excreted by the body. Therefore, excessive consumption of food coloring can also cause black diarrhea. Particularly dark and undiluted colorants are suitable for this.
If black diarrhoea cannot be clearly attributed to the consumption of food coloring, other causes such as bleeding should be excluded in any case. The same applies if the diarrhea persists for several days after the consumption of food coloring. An excess of iron is excreted from the body via the gastrointestinal tract.
So anyone who takes iron tablets in too high a dose, or in whom the iron from the preparations cannot be absorbed well through the intestines, will “get rid of” the iron with the stool, so to speak. The diarrhea is then black in color – and therefore difficult to distinguish from blood. If taking iron tablets could be a possible cause of the black diarrhoea, you should consider discontinuing or reducing the dosage.
Antibiotically effective drugs can indeed cause diarrhoea: This is due to the fact that when taken orally they can attack the natural bacterial flora of the intestinal mucosa. The bacterial residues, which are then excreted with the stool, can cause a discoloration of the diarrhea, but the color is rarely black. Completely black diarrhea is most often caused by bleeding in the upper gastrointestinal tract, which is not usually caused by antibiotics.
However, if the diarrhea persists after taking the antibiotics, medical advice should be sought. Dark colorants ingested with food can also cause discoloration of the stool. Such foods include red wine, to which additional colorants are sometimes added to make the color appear more intense. It should therefore be checked whether red wine was consumed before the occurrence of black diarrhea, as this could be the trigger for this.
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