A 4-year-old girl was hospitalised with constipation because her school's toilet roll rules left her too scared to relieve herself when she used the bathroom.
Cardiff school Kitchener Rd Primary refuses to put toilet paper in the student cubicles.
Instead, the school makes the students aged between 4 and 11 take what they think will be enough paper from a single dispenser before going to the bathroom.
The girl's mother, Fahmin Khanum, said the policy has meant many children have soiled themselves and others are too anxious to use the bathroom.
Khanum revealed her 4-year-old was taken to University Hospital of Wales for three days in October with intense stomach pains.