Despite the registered nurse documenting the woman's pain score as four out of five, the junior doctor discharged the woman, assessing her condition as constipation.
Hill made an adverse comment saying the junior doctor had the responsibility to consider appropriate investigations and to discuss the woman's presentation with a senior doctor.
Hill considered the junior doctor's diagnosis of constipation, based on the history and examinations performed, was inappropriate.
As a result, Hill found the junior doctor failed to provide services to the woman with reasonable care and skill.
The woman's pain continued and the next day she made an appointment with her GP who assessed her and arranged urgent referral to the surgical assessment unit.
The unit identified that the woman had a twisted ovary. She underwent surgery to remove the ovary.
The junior doctor told the Health and Disability Commission: "I am truly sorry about the misdiagnosis and about the apparent lack of appreciation for her pain."
Hill ordered the doctor to write a formal letter of apology to the woman and recommended the district health board use an anonymised version of this case for the wider education of its medical registrars.
In another Health and Disability report released today a man was diagnosed with prostate cancer after his GP failed to follow up concerning test results that showed high levels of prostate-specific antigen (PSA).
The commissioner recommended the GP provide a written apology to the man's family.