Hi and welcome to the site!
In reference to menopause, hormones play a huge role in digestive health. Our gut has more serotonin than our brain. At the peak of my IBS woes I was on birth control, then I got off and felt about 75% better. I had to get back on (for reasons other than to prevent pregnancy), but I asked for a "low hormone" pill and it hardly affected me at all.
Here's a great little article about IBS and serotonin.
It's quite possible that your troubles are post surgery related. 2 weeks really isn't that long. Have you spoken to your doc about all your symptoms?
Did you take any antibiotics through all this? If so, it might behoove you to start on probiotics to try and help your gut get back in line. Probiotics also do wonders for constipation.
about the colonoscopy... Yes, you should have the procedure done. Isn't 50 the suggested age to start getting them done regularly? Regardless, it might make you feel better. The prep is the worst part, because let's face it, we all hate having D. BUT, afterwards, when you're all cleaned out, it's a great feeling. Besides, it's reassuring to know the doc has been in there to check for abnormalities.