Green bowel movements are a rather rare occasion for consultation with a doctor and in most cases they are not associated with a real disease value. One-off events are usually due to irregularities in the course of digestion. Only a repeated or frequent occurrence of green bowel movements should give cause for concern and further clarification. Here, too, a whole range of potential causes open up, which can affect either the liver, the gall bladder or the intestine.
Causes of green bowel movements
- Too much bile/inadequate bile absorption: Bile is secreted to help digest dietary fats. If there is too much bile or it is not properly reabsorbed, green coloring may occur
- Green coloration due to food: Both green food coloring and the natural green colorant chlorophyll can cause green coloring of the stool
- After antibiotic intake: antibiotics kill a large part of the “good” bacteria in the human intestine, which considerably limits the absorption and preparation of the food rice in the intestine.
Bile is usually the first thing that the doctor will think of when a patient reports greenish bowel movements. Normally, the bile in the gastrointestinal tract serves to make fats in food more easily absorbable.
The bile is usually also reabsorbed to a large extent. If the absorption in the intestine is disturbed or too much bile is produced, or if the absorbed food is transported much faster through the intestine, e.g. due to diarrhoea, the bile cannot be reabsorbed and is then excreted as a greenish dye that has mixed with the stool. Food coloring can also be a simple as well as harmless reason for a green coloring of the stool.
While a small amount usually does not cause a color change, intensive use of green dye can easily cause green stool. The more unprocessed the food coloring is absorbed, the more green coloring occurs. But other green foods with a high chlorophyll content can also cause a greenish color change.
Green sauce or pea puree are examples of this. Green stool as a result of taking antibiotics is also not uncommon and is caused by the fact that the antibiotic not only attacks the bacteria it is supposed to work against, but also affects bacteria that are at home in the human intestine. Since the antibiotic is swallowed, it primarily affects the intestinal flora and is only absorbed to a small extent from the intestine and then transported via the blood to the place where it should actually work.
Rather the majority of the antibiotic works in the intestine and kills the bacteria there. These are important, however, in order to be able to digest the absorbed food in its entirety and extract the maximum amount of nutrients from the food. If the antibiotic kills these bacteria, the proper digestion of normal food will no longer function completely.
The intake of iron tablets leads to changes in the bowel movements of almost all people. This is due to the fact that not all the iron can be absorbed in the intestine and is therefore simply excreted again through the bowel movement. As a rule, however, the color of the stool produced in this process tends to be very dark brown to blackish and not classically green, as would be the case, for example, with stool changes caused by bile. However, the doctor should always be informed about taking iron tablets.
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