Menstruation is not allowed to do colonoscopy, because at this time to do colonoscopy will affect the results of the colonoscopy, generally recommended that the menstrual period after the clean 3-7 days and then do the colonoscopy, because menstruation human body resistance is reduced, prone to adverse reactions, such as infections, and serious intestinal bleeding, this test is a kind of traumatic examination, so should be avoided during the period to do. Menstruation should pay attention to rest, diet should be light, do not eat spicy food, pay attention to warmth, avoid strenuous exercise, so as not to cause an increase in menstruation, but also pay attention to personal hygiene, to avoid causing infection. Do colonoscopy should pay attention to the following points: 1, 3 days ago should eat liquid food. 2, avoid eating vegetables, fruits and may lead to flatulence food, such as milk, so as not to have an impact on the results of the examination. 3, the day of the examination need to fasting, oral cleansing solution or the use of enemas to wash the bowel.