It is recommended to systematically inspect the appearance of your stool: while the classic brown color (linked to bile) is normal, a clay-like shade or the presence of blood should be a cause for concern. Conversely, unusual colors (purple, green) or multicolored segmented stools are generally benign and linked to recent diet and variations in transit.

noli's read

The advice to regularly observe the appearance of one’s stool to monitor digestive well-being is widely supported by health guides from institutions such as the Cleveland Clinic and the Mayo Clinic. These expert panels confirm that the usual brown shade comes from the natural degradation of bile pigments by our gut microbiota. Similarly, light or 'clay-colored' stools signal a lack of bile, which most often points to a blockage in the digestive ducts, a fact validated by a solid consensus of clinical experts. The explanation regarding purple or reddish hues linked to the colored pigments of certain foods (such as beets or berries) is also based on well-established clinical observational data. Conversely, the idea that two-toned or segmented stools result from a simple mechanical juxtaposition of different meals (such as dinner mixing with breakfast at the level of the pelvic floor) is an appealing explanation but one that lacks direct scientific evidence. Although transit time varies from one ingredient to another, as shown by observational transit-tracking studies, digestive matter generally homogenizes in the colon, and such color variations within a single stool are more likely to stem from local variations in flora or partial digestion.

the sources

No named source held this one up — that absence is part of the verdict.