Pressures measured by manometric solid-state catheters may differ according to the type of the catheter and specific anatomy and physiology of anorectum.

The aim of the study is to establish the difference in recordings between 2 types of anorectal catheters used in pediatric patients and to validate the most appropriate way to diagnose of functional disorders.

Patients enrolled in study will be investigated by both types of anorectal catheters, first by anorectal high resolution flexible, thinner, solid-state catheter and after that with rigid, thicker, solid-state catheter. Both procedures will be undertaken during one session. There will be used standard protocol of the procedure that measures conventional manometric parameters (resting pressure, squeeze pressure, bear down manoeuver, thresholds of sensation and recto anal inhibitory reflex threshold.

Inclusion Criteria:

• Functional Constipation
• Fecal Incontinence
• Parental Agreement

Exclusion Criteria:

• After surgery on lower gastrointestinal tract
• Diagnosis of inflammatory bowel disorders
• Diagnosis of other disorders present in anorectal area, that may influence anorectal pressures
• Lack of parental agreement