When is abdominal pain a cause for concern?

Alarm symptoms: I become concerned about abdominal pain when patients have associated bloody stools / vomiting, weight loss, family history of colon cancer / stomach cancer, anemia (low blood counts) and persistent vomiting. These symptoms will make me pursue further work up.

Pretty much always.: We shouldn't feel pain, especially acute pain. So pain in the abdomen is really always a concern inasmuch as its cause. Now, not all causes of abdominal pain are dire and fatal and such, but if you're having a new pain in your abdomen the cause should be elucidated.