Experiencing multiple concurrent functional gastrointestinal disorders is associated with greater symptom severity and worse quality of life in chronic constipation and defecation disorders

Background: Recent community-based studies have demonstrated that experiencing multiple concurrent functional gastrointestinal disorders (FGIDs) is associated with increased somatization, worse quality of life (QoL), and greater health care utilization. However, the presence of multiple overlapping FGIDs is unstudied specifically in chronic constipation and functional defecation disorders (FDD). We investigated the prevalence and impact of additional nonconstipation FGIDs on constipation severity, anorectal physiology, anxiety and depression, and QoL, in patients with chronic constipation and FDD. Methods: One-hundred and forty-six consecutive patients with functional constipation or irritable bowel syndrome (IBS-C/IBS-M) presenting to a tertiary referral Neurogastroenterology Clinic were studied. In addition, 90/146 (62%) qualified for FDD due to abnormal defecatory physiology. Patients underwent comprehensive baseline assessment comprising anorectal physiology, Bristol Stool Chart, Rome questionnaire, Knowles-Eccersley-Scott-Symptom (KESS) constipation score, Hospital Anxiety, and Depression Scale, and modified 36-Item Short Form Health Survey (SF-36) for QoL. Additional FGIDs were diagnosed using Rome III criteria. Key Results: Additional nonconstipation FGIDs occurred in 85% of patients, with a mean of 2.1 (SD 1.6) additional FGIDs. Patients with four or more additional FGIDs experienced greater constipation severity compared to those with no additional FGIDs (p = 0.004). Comorbid FGIDs were associated with worse SF-36 scores for physical functioning (p < 0.001), role-physical (p = 0.005), bodily pain (p < 0.001), vitality (p = 0.008), social functioning (p = 0.004), and mental health index (p = 0.031). Conclusions and Inferences: Functional gastrointestinal disorders comorbidity is highly prevalent in chronic constipation and defecatory disorders, and this is associated with greater symptom severity and worse QoL. Multimodal treatments targeting comorbid FGIDs may lead to superior outcomes.