Richard, I hope you can get this figured out. You don't say exactly how thick your output is, but (if it's thick) you might get some relief from thinner output (more water or Magnesium Sulfate, as Rachel suggested). You might try a tap water enema, again as Rachel described. Even if these are not acceptable in the long term, they may give you enough relief so you can calmly make longer term plans.

If your surgeon can't figure this out, it might be wise to get another opinion, even if she's a genius. She doesn't know everything, and she may not know how to fix your problem. You may have a mechanical pouch defect, or you may have a functional problem that biofeedback or pelvic floor therapy could help with. Good luck!

If it hurts too much to consider an enema, might you have an anal fissure? They can hurt so much that it's extremely difficult to poop. They are difficult to clear up, but there are definitely treatments.

Chunky is not so good. It's best to assess hydration not by how much you drink, but by how much you pee. Your urine should be light-colored, and at least a few times daily with reasonable volume.

So much of what we deal with is trial and error for each of us as individuals.  What does the job for one person may not work for another.  After reading your description of what is happening, I'd like to suggest you try the following:  Eat an apple once a day.....skin, included!  Whenever I feel "plugged" an apple a day does keep the doctor away, for me!  I'm thrilled I found a simple solution which works for me.   Best wishes!

See, for me, an apple potentially can cause blockage at the outlet. I have to be very careful with raw apples; peeling them helps. They also are a SIBO trigger for me. 

Sometimes I find that gas blocks stuff from exiting. I tried doing a downward-dog pose (get down on all fours--head low--butt high) and I could hear the gas move up out of the way and then I could eliminate. As Rachelraven says, changing positions may help.