People I'm around have had diarrhea for the past 5 days. They obviously caught a bug. Can I only catch it from them thru the faeco-oral route?

Yes. Wash your hands frequently and get out the Clorox. Try to isolate yourself as much as possible. They should be encouraged to use good hygiene as well. Your company should consider this an outbreak and obtain stool samples. All the best, to good health!