Much like students of any stripe, medical students often have many items they need to have on their person during their daily sojurns to lecture halls and wards. While this may be a bit dated, my go to bag in medical school was an earlier version of the Targus Checkpoint-Friendly Mobile Elite Laptop Bag. The other items I typically would have in my bag were:

• Littmann Cardiology III Stethoscope - a nice gift from a good friend, and quite useful on wards
• Penlight
• Mobile device - at the time, a Palm Pilot, but these days I would highly recommend an iPad Air 2 due to the wide range of medical apps, light weight, and long battery life. 
• First Aid for the USMLE Step 1 - until I passed at least, haha
• Nalgene water bottle
• Clif Energy Bar - my current fav, but any snack works
• Pens - always get clickable, black ink pens. And always have an extra one because they will get stolen. Trust me. 
• Highlighters
• Pocket Medicine - probably should have carried this more during medical school, but was definitely a must-have during internship, so why not start early?
• Pager - [grumbles]