If the menstrual blood is discharged like rotten tissue, there are several possibilities: the first is the so-called membrane-like menstruation, during menstruation, the uterine lining is shed, but often in the form of fragments, which can not be seen without careful observation, when the endometrium is over-active, or the endometrium is inflamed, then a large piece of the endometrium will be discharged. This is often accompanied by menstrual cramps, because contractions of the uterus are required to expel the large pieces of endometrium, which is why it is accompanied by menstrual cramps. The second possibility is whether there are symptoms of miscarriage, if there is a history of menopause, and then menstruation will appear like rotten tissue, may be caused by miscarriage. It is recommended to check blood HCG or urine HCG to distinguish whether it is a miscarriage.