My guess is that you can probably wait. Bear in mind however, that that is only a guess. You may have picked up a parasite or have some other form of GI distress. When you say that you ate something "questionable", I have this vision of raw fish or sushi.(?) With everything that is going on over here (U.S.) with the spinach and e-coli, I am reminded of some food poisoning symptoms such as bloody diarrhea. Utilize some common sense but monitor your bodily functions -- If medical help is not too difficult to obtain, I would certainly consider it. If you have had IBS for seven years, you should be able to distinguish between familiar symptoms and those which are new. Not being knowledgeable about China, I certainly can't offer advice on medical facilities, treatment or sterile environments in rural areas. The bleeding may be from aggravating a hemmie or straining. At the very least, you can give it the attention it deserves once you are back in Beijing. Best of luck. Hope that you are able to enjoy the rest of your trip.John