When you install a pump all kinds of crap goes in with the pipe. If you hopefully used Poly, it laid in the chicken manure while being set. Its certain to not pass a test.
I just did a 240 footer, 6" - 1 gallon + of clorox, 6% [ comes in big bottles, 1.2 gallon I think and at more commercial oriented stores] I think basic bleach is 3%.
You MUST rig up a return line to the well - hopefully the well guy left you a port or plug in the cap. Dump the chlorine and start recirculating water from a hose bib for about an hour down the well. Dont use other taps in that hour. Then run water through all your taps just until you smell chlorine. Shut it all down overnight. run all taps in the AM and flush out the chlorine.
Other guys here will cry about using store bought bleach, but it works fine. I think in the "stickies" there are more ideas on this. I always get a pass test after such treatment.
If E-coli continues, you will have to check the well and see if it is sealed correctly. The manure should not make it to the water table.