A 62 year old woman presents to her primary care provider with a long history of constipation. Along the last two years, she has tried all kinds of laxatives, high fiber diet and drinking large amounts of water with little or no improvement. She has to strain excessively to defecate and when she defecates, she feels not satisfied and needs to go further but she canít. Her last menstrual period was 7 years ago and she doesnít take any pills. Her past, surgical and family history are unremarkable. On examination, there is no distress, her vital signs are within normal limits and her abdominal examination is normal. Digital rectal examination shows no fissures, scars or masses. It reveals tonic contraction of her anal sphincter with hard stools in ampulla. Her lab tests reveal normal thyroid function and normal metabolic profile.