Anorectal manometry and high-resolution anorectal manometry (HRAM) are becoming the investigation of choice for understanding the pathophysiology of chronic constipation with or without fecal incontenance in children in many institutions. In high resolution anorectal manometery we are able to gain information whether the symptoms are related to sphincter dysfunction, impaired sensation, or pelvic floor dyssynergia

Primary objective: To assess different patterns of anorectal manometry in children with chronic refractory constipation with or without fecal incontinence.

Secondary objective: To determine the effectiveness of different modalities of treatment of chronic refractory constipation based on the anorectal findings. To assess the safety ,tolerability and effectiveness of lubiprostone in pediatric age group with chronic refractory constipation. To assess the effect of elimination of cow milk products in patient with chronic refractory constipation.

Inclusion Criteria:

1. Children and adolescents aged from 4 to 16 years.

2. Participants fulfilling Rome IV criteria for the diagnosis of functional constipation.

   At least 2 of the following present at least once per week for at least 1 month:

   • 2 or fewer defecations in the toilet per week
   • At least 1 episode of fecal incontinence per week
   • History of retentive posturing or excessive volitional stool retention
   • History of painful or hard bowel movements
   • Presence of a large fecal mass in the rectum
   • History of large-diameter stools that may obstruct the toilet The symptoms cannot be fully explained by another medical condition (Hyams et al., 2016).

3. Participants who have chronic refractory constipation. Chronic refractory constipation (CRC) is defined as children who are unable to pass stools in spite of being on maximum laxative therapy and require daily rectal stimulation in the form of enemas or suppositories to pass stools 4-Is willing and able to keep a diary on his/her own and willing and able to complete a questionnaire.

5-The participant or, when applicable, the participant's legally acceptable representative signs and dates a written, informed consent form and any required privacy authorization prior to the initiation of any study procedures.

Exclusion Criteria:

• participants who have anorectal malformation
• participants who have neurological disease affecting lower limbs
• Has a history of hypersensitivity or allergies to lubiprostone