Anyone else have hemerrhoid surgery?

Hello everyone! I'm new here and recently had a consultation with my surgeon for the gastric sleeve surgery. I'm scared and excited all rolled into one!

I had a hemerrhoidectomy in April 2015 and constipation is a major concern for me in having this surgery. Is there anyone else out there that has had a hemerrhoidectomy that also had the gastric sleeve surgery? What is your experience with constipation after surgery? Any tips on how to avoid constipation?

My surgeon suggested Milk of Magnesia and dissolvable Fiber like Metamucil. Do these suggestions really work for you all?

I seek honest answers from people that have actually gone through these experiences and don't really rely on rehearsed answers that doctors seem to provide.

Thank you all in advance for your help and advice