Normal chair color
Stool consists of unabsorbed food components, intestinal cells, mucus, digestive secretions, xenobiotics, bile pigments, water, and intestinal bacteria. It is usually yellow-brown to brown in color. It comes primarily from the bile pigments (bilirubin), which are metabolized by the intestinal flora to brown stercobilin, among other substances: Erythrocytes Hemoglobin Hem Biliverdin (green) Bilirubin (yellow) Urobilinogen Stercobilin (brown).
Change in stool color
Infants:
- The newborn’s first stool, called meconium or infantile sputum, is greenish-black in color. The excretions of babies fed on breast milk are usually liquid to mushy and predominantly yellowish in the first months of life.
Various medications can cause a change in stool color. Professionals should ideally point out this fact to their patients when dispensing, so that no uncertainties arise:
- Activated carbon: black
- Barium: white, gray
- Beta-carotene: yellow
- Bismuth: black
- Iron: dark, black
- Orlistat: fatty stool, yellow
- Rifampicin: brown-red, orange
- Senna: yellow
Food also has an influence:
- Blueberries: black
- Spinach, chlorophyll: green
- Blood: black
- Beet: red
- Flesh: dark brown
- Food coloring
A change in stool color may indicate disease:
- A light, clay-colored stool may occur as a result of liver, gallbladder or pancreatic disease. It may be accompanied by accompanying symptoms such as loss of appetite, jaundice and itching. A medical diagnosis is mandatory.
- Bleeding in the upper digestive tract leads to a black stool, called tarry stools (melena).
- The longer the intestinal passage continues, the darker the stool. So in diarrheal diseases it is rather light, in constipation dark.
Bright red, fresh blood is often caused by hemorrhoids or an anal fissure. Bleeding in the lower digestive tract can also be responsible. However, blood is not necessarily visible – hidden blood in the stool is called occult.
When is clarification necessary?
If there is no obviously harmless cause – such as food or medication – contact should be made with a medical professional. This is because changes in stool color can sometimes be due to a serious illness, such as a stomach ulcer, liver inflammation, or cancer.
