Can a deep tissue massage cause intestinal upset 2-3 days after the massage?

Probably not. Any intestinal disturbance would have occurred during the treatment session, if it occurred at all. Plus, deep tissue massage should never be performed on the intestines. That is outside the scope of deep tissue massage. However, if you suspect that there could be a problem, check with your massage therapist, a general practitioner, or go to the emergency room of your local hospital.