Three questions!

Hair loss can occur with any major trauma, physical or emotional.  It's caused by an increase in the number of hair follicles going into shedding mode.  Normally, a small % are dormant and we lose around 100 strands per day.  Surgery, childbirth and other shocks to the body can cause a lot of hair loss that starts a few weeks or months following and lasts up to 6 months.  I lost a lot of hair with my band, no increase in loss with my gallbladder removal,