Prevalence of Abdominal Pain Related Functional Gastrointestinal Disorders in Pediatric Recipients of Hematopoietic Stem Cell Transplant

Background: Consultation for abdominal pain (AP) in pediatric patients following allogeneic hematopoietic stem cell transplant (HSCT) is common. Non HSCT related GI inflammation (infectious and non-infectious) has been associated with post-inflammatory abdominal pain and functional gastrointestinal disorders (FGID) in as high as 60% of cases.  The presence of AP and FGIDs after HSCT has not been described.  We hypothesized that AP is frequent after HSCT given the inflammation from conditioning, GVHD and infection.  Methods:  Patients >2 years from HSCT were offered a Questionnaire of Pediatric Gastrointestinal Symptoms.  Those with active gut GVHD were excluded. After completing the surveys, chart reviews were performed focusing on demographics, transplant characteristics, adverse events and long-term outcomes. Results: 48 patients completed the survey;7 (15%) had abdominal complaints.  3 patients were diagnosed with AP related FGID (dyspepsia, IBS, functional abdominal pain); 4 had AP that did not fit criteria for diagnosis. The group with AP were transplanted for high risk malignancy (71%) – ALL(2), AML (1), Anaplastic Lymphoma (1) and Stage IV Neuroblastoma(1).  There was an increased incidence of total body irradiation (TBI) containing regimens (57% vs 39%) in patients with AP, but conditioning regimen intensity ie. myeloablative versus reduced intensity (MA/RIC) was not associated with AP.  There was an increased incidence of aGVHD (43.9% vs 29.3%), however surprisingly incidence of GI aGVHD was equal between groups.  Those with AP had a higher incidence of second transplants (28.5% vs 4.9%), which were performed for relapse. The AP group also had more frequent abdominal infections (40% vs. 15%). The time interval from HSCT in the AP/FGID group is shorter (4 years), compared to the non-AP group (6 years), p=0.029; however there were no other significant demographic differences between the two groups. Conclusions: AP and FGIDs are common after HSCT in children. AP was more frequent in patients <5yrs from HSCT. Data suggested that TBI, abdominal infections and relapse may be associated with later development of abdominal pain. Larger studies are needed for further evaluation and to confirm these finding.  The investigation of post-HSCT AP and FGIDs may help understand the role of inflammation, stress, coping and families on the development of functional abdominal pain.