I have read your post but I am unable to answer your specific request for reassurance from someone that has had a hysterectomy. The procedure that are referred to are primary intestinal condition; small bowel prolapse, also called enterocele. It occurs when the small intestine descends into the lower pelvic cavity and pushes at the top part of the vagina, creating a bulge. Also sometimes women present with post-hysterectomy vaginal vault prolapse in conjunction with small bowel obstruction.
I can't ever remember the topic of hysterectomy being raised in the forum. If your surgery went well without complication I would say you are OK to flush should you require. Bear in mind that one flush in isolation may not be sufficient and often a series are carried. It is also very important to look after your lifestyle and there is plenty in Moritz book about eating well and being active.