Inflammatory bowel diseases (Crohn’s disease and ulcerative colitis) in approximately 25% of patients are diagnosed under 20 years of age and the incidence continues to grow. The disease occurs with periods of exacerbation and remission and leads to deterioration in the quality of life and severe complications, so early correct diagnosis is essential. The symptoms may vary, yet a typical clinical picture consists of chronic abdominal pain, (bloody) diarrhea, and general weakness. The symptom, which always requires expanded diagnostics, and may occur in the course of inflammatory bowel diseases is a growth inhibition of the child. Basic laboratory tests, stool examination and abdominal ultrasound examination should be performed by the GP as initial research and initial differential diagnosis. Further diagnosis of inflammatory bowel diseases requires hospital conditions, and the correct diagnosis allows the implementation of appropriate treatment aimed at reducing pain, restoring normal growth and prevention of surgical interventions.