RESUMEN
Melanosis coli is a dark to brown pigmentation of the colon due to lipofuscin deposition within the cytoplasm of cells. It is a benign condition associated with excessive use of laxatives, particularly those that are anthracene derivatives and common herbal remedies like Cassia Angustifolla (senna). It is usually asymptomatic and diagnosed incidentally during colonoscopy or histopathologic evaluation. We present a case of a 56-year-old male patient who presented with diarrhea of 3 months duration, which started after he began to use California herbal tea for his constipation. Colonoscopic evaluation revealed an intense pigmentation throughout the colon suggestive of Melanosis coli, which was confirmed on histopathology. In patients with prolonged use of California herbal tea and dark to brown pigmentations of colonic mucosa on colonoscopy, there should be a high index of suspicion for Melanosis coli. And patients should be aware of the risk of developing Melanosis coli following prolonged herbal tea use. The findings presented in our case are in support of few previous literature that showed relations between chronic herbal tea use and Melanosis coli.