What Is Causing My Mother's Severe Abdominal Pain?

hello my mother is 50 yrs old She had severe abdominal pain for 2 to 3 weeks. she is a doctor and she suspected it to be typhoid 2 weeks ago and had taken treatment for it it slightly decreased but yesterday she had severe pain in the abdomen again so today she had gone for an ultrasound......in the uterus there were many anechoic areas and the endometrium lining was 67 mm i was told by my sister that there was a need of biopsy......what is the disease or problem and is it serious?