I had trochanteric bursitis last year while training for a marathon. just started running again. how can i prevent recurrence?

Stretching: Has to do with tight it band. Can be related to running technique, pelvic motion, etc. Usually an injection and pt for aggressive stretching will allow return to activities.

See physiatrist: See physiatrist or perhaps physical therapist to examine your technique. Also check whether the treatment completely resolves the issue or is only partial.