Has anyone experienced this -- feeling the urge to go, and while walking to bathroom you feel the sharp pain pre-bm, and then also during it as well? Also, any thoughts on miralax? Ive been using it regularly, but my dr made the suggestion to use it less and rely more on things like benefiber.

Yes, because once the stool is that far down in the rectum, it would already be pushing on the fissure. I can't answer your question about Miralax though, because I have never used it.

I used Miralax for a while. It worked at first but became less and less effective over time. I can't speak to Benefiber.

I find pears, apples and bran cereal with lots of raisins or soaked prunes keeps things moving and soft.