the way you describing the symptoms, it seems like she is having "irritable bowel syndrome
(IBS)". but need further hsitory and some work up. is she still constipated? what is the stool consistency..hard/lumpy or loose. did you noticed blood in stool
. some times a simple anal fissure
can give symptoms like this. but as you have checked yourself that there is no redness or anything in the anal verge, this should be ruled out.
I am thinking of IBS because of the typical symptom of relief of pain with passage of stool. she needs to be investigated. However, i will advise some dietary changes to her..
1. eat small but frequent feeds (avoid large meal)
2. avoid food with high fat content, milk and milk products, caffeine and drinks with caffeine and artificial sugar
3. avoid food which causes gas like bean, cabbage
4. avoid meat, can take fish
5. give green leafy vegitables high in fibre
6. can add fibre suppliment
7. if constipation
, can give laxatives
take an appointment with your local pediatrician
for examination, more advise/ drug treatment