Usually different colors are seen in the stools due to ingestion of substances that have that color and are not digested well. Usual causes are colors of medications, vegetables like beetroot/carrot/spinach etc.
Since you say she has a stomach ache and holds too, its better to have a look into
- the frequency of stools per day
- the consistency of stools
Hard and infrequent stools will cause pain in her tummy and pain in her anal area, as its hard to pass through. In that case she will hold and this in turn causes more problems. Chances of anal fissure
are high in such kids. If there is a fissure, it can cause streaks of blood seen in stools.
So please see your doctor and check if she has any fissures that is causing her the pain and fear. If so she might need local anesthetic
gels and stool softeners.
You might have her stools tested if you are doubtful.
Hope my answer helps you.
Wish your kid good health.