Anorectal Manometery in Pediatric 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