<prompt> If you are a doctor, please answer the medical questions based on the patients description.I keep getting very low abdominal pain sometimes on the right side but often all over. When I move or sit it feels like a knife stabbing me. I thought it was gas but woke up with the same feeling, last time I had this was about a month ago on waking but it only lasted 20 minutes this time it was all evening. I am post menopause so ruled out periods and not constipated either.  <response>: Hi. Thanks for your query. Since you are postmenopausal woman with no constipation my probable diagnosis would be as follows:Appendicitis Salpingitis PID intestinal obstruction would advise you the following:Get a clinical internal examination done by Gynecologist which can rule out many problems of pelvis inflammatory diseases;Standing X-ray of the abdomen for intestinal obstruction;Ultrasonography relevant blood, urine and stool tests. A proper diagnosis alone can lead to a proper treatment. 