Took 5g Flagyl over 6 months for repeated diverticulitis, emg now shows slow nerve velocity where previous emg normal-- coincidence?

Known to cause. Flagyl ( metronidozole ) prolonged use known to cause both peripheral and autonomic neuropathies , speak to your doctor , for alternative medication. If you are suffering for over 6 months surgical resection is also an available option.
No. Flagyl can cause neuropathies (nerve problems) that result in abnormal nerve conduction studies or emgs.