Indican is a colourless organic compound, soluble in water, naturally occurring in Indigofera plants. It is a precursor of indigo dye.
Indican is a glycoside. Its hydrolysis yields β-D-glucose and indoxyl. Reaction of indoxyl by a mild oxidizing agent, eg. atmospheric oxygen, yields indigo dye.
Indican is formed by an abnormal metabolism of tryptophan. Indican is a by-product of putrefaction (protein degradation), usually in the intestine, but possibly in other locations as well. Putrefaction is the anaerobic bacterial decomposition of proteins - not ideally the healthy way for your body to deal with proteins. When the product of this putrefaction (called indole) is absorbed into the blood stream, an increase in urinary indican is seen. This increase can also be seen if bacterial decomposition of body tissues or fluids occurs, as in gangrene, absesses, etc.
Among the pathologic conditions in which urinary indican is likely to be elevated are hypochlorhydria (low stomach acid production), inhibited peristaltic movement (the involuntary muscular "waves" that move food through your bowel), and poor production of digestive bile secretions from the gall bladder and liver. Elevated indican is rather rare in simple constipation, but often high with diarrhea. It is generally a good indicator for the poor breakdown of proteins accompanied by gastrointestinal permeability (the "leaky gut").