Hi thanks for choosing HCM for your query. Diverticulosis is due to formation of pouches form in the wall of the colon. Normally, a diet with adequate fiber (also called roughage) produces stool that is bulky and can move easily through the colon. If a diet is low in fiber, the colon must exert more pressure than usual to move small, hard stool. A low-fiber diet also can increase the time stool remains in the bowel, adding to the high pressure. Melanosis coli is dark brown pigmentation of the colon that occurs with the use of laxatives containing anthraquinone, such as senna. It can develop within a few months of use, and it can disappear in a few months if the use of the laxative is discontinued. Melanosis coli is considered a benign lesion. Since you have been using Smooth Move tea for the treatment of IBS, the major ingredient in that tea is Senna which is a laxative. So, the use of Smooth Move tea might have resulted in the development of melanosis coli. You are therefore advised to visit your doctor for the possible change of medicine for the treatment of IBS. I hope your doubts have been cleared. Give your valuable feedback.