Generally speaking, breast cancer patients can have colonoscopy after one month after surgery, but it should be noted that patients who need chemotherapy after surgery should try to avoid having colonoscopy during chemotherapy. One month after breast cancer surgery, most of the patients’ surgical incisions have healed, and the patients’ diet as well as physical condition have largely returned to normal. If the contraindications to enteroscopy such as intestinal bleeding and infection are ruled out, the general breast cancer patients are allowed to do enteroscopy. However, it should be noted that some patients need to do chemotherapy after breast cancer surgery, and after chemotherapy, some patients may have gastrointestinal adverse reactions, or myelosuppressive adverse reactions such as lowering of white blood cells and platelets, and colonoscopy is likely to aggravate these adverse reactions, therefore, try to avoid doing colonoscopy during chemotherapy.