Functional Abdominal Pain Disorders

Chronic abdominal pain is common among children, and the majority of cases are attributed to functional abdominal pain disorders. One approach to treating these disorders is by using psychological therapies. This clinical trial aims to see how well pre-recorded guided imagery therapy sessions help children's abdominal pain when delivered via a mobile application (app) on a smartphone or tablet. Participants will complete a baseline abdominal pain and stooling diary to determine eligibility, as well as other surveys. Eligible participants will be given access to the guided imagery therapy mobile application. This intervention asks participants to listen to a 10- to 15-minute GIT session 5 out of 7 days per week for 8 weeks, in addition to their usual care for their abdominal pain. Then, participants will complete another abdominal pain and stooling diary, along with other psychometric surveys, at the end of this intervention period. Participants will also collect another diary and surveys 3 months post-treatment.

The goal of this non-inferiority randomized controlled multi-center trial is to investigate the use of video consultations in the follow-up care of children aged 4 - 18 years old with functional abdominal pain disorders (FAPDs). Video consultations will be compared to face-to-face consultations. Clinical outcomes and patients' and parents' healthcare experience will be compared between both groups. Primary outcome is adequate relief after 12 weeks: the hypothesis is that video consultations are not inferior to face-to-face consultations regarding clinical outcomes and that adequate relief will be the same for both groups. Participants and/or parents will be asked to complete a diary for 1 week and a questionnaire after every consultation: at baseline, after 6 weeks and after 12 weeks.

The goal of this observational study is to learn about spatial and temporal nociceptive filtering in adolescents with chronic overlapping pain conditions (COPCs). The main questions it aims to answer are: 1. If spatial and temporal filtering of nociceptive information is disrupted in youth with COPCs compared with youth with localized pain conditions and healthy controls. 2. If disrupted nociceptive processing at baseline is associated with the transition from a single localized pain condition to COPCs in youth. Participation includes: * quantitative sensory testing * blood draw * sleep assessment * questionnaires