Hi.
Thanks for your query.
Noted the history about your 21 year daughter and understood the concerns.
The basic reason behind IBS that is
irritable bowel syndrome is stress and/ or
anxiety. As she comes home she is getting better means the new atmosphere is not suitable for her.
Secondly an attack of food
poisoning may indeed be exacerbation of IBS.
I would advice her the following:
First of all to get appropriate clinical evaluation by a Gastroenterologist.
Tests of blood, urine and stool.
Ultrasound/ CT scan of abdomen.
Colonoscopy.
If all the investigations are normal then only to say this to be IBS and treated with symptomatic and
psychotherapy.
It is possible that the atmosphere in new college is not suitable for her and may need changeover.
If something specific is found out, may need treatment accordingly.