A hysteroscope is a narrow instrument that is inserted into the uterus through the cervix. It allows a physician to look directly at the inside of the uterus. If an operative hysteroscope is used, then minor surgical procedures such as polyp removal can be done at the same time. A procedure done with a hysteroscope is called a hysteroscopy.
Insertion of the hysteroscope causes a cramping sensation similar to a strong menstrual cramp or contraction. Depending on the woman's tolerance for pain and on the length of the procedure, sedation may be used.
Hysteroscopy can cause uterine bleeding. There is halachic debate as to whether such bleeding can be considered dam makkah (bleeding due to trauma, which does not make a woman niddah), or whether all uterine bleeding – even due to injury – will make her niddah.
Hysteroscopes range from 4-8 mm in diameter (the physician can be asked about the diameter of the instrument that will be used). There is halachic debate as to whether this is is wide enough to make a woman niddah through cervical dilation.
Therefore, a specific halachic question should be asked about whether a hysteroscopy will cause niddah from either the bleeding or the cervical dilation. Depending on the ruling, it may be possible to schedule the procedure in a way that will minimize the time one is niddah.