What Causes Painful Bowel Movement After Total Laparoscopic Hysterectomy?

Hi, im 5 days post op Total LH, conservation ovaries and morcelation of uterus with fibroid. My bowels finally opened yesterday (day 4), but since then, any bowel movement eg, gas or even tiny solid is excrutiating, like knives, particularly at the rectum and anus. I am drinking water and warm pear juice and have used movicol twice. Is this usual or may there be some damage to the bowel or nerves.?