Abstract
Purpose Stool burden on abdominal radiographs is not reflective of constipation, perhaps because of variable fecal shadowing or limited inter-rater agreement. These limitations are hypothetically mitigated by computed tomography (CT). This research aimed (i) to evaluate whether bowel movement frequency, stool form, or a diagnosis of functional constipation correlate or associate with stool burden identified on CT, and (ii) to investigate whether physicians use CT in their assessment of a patients' bowel function. Methods Patients attending for non-emergent abdominal CT imaging were invited to participate by completing a bowel questionnaire. Stool burden identified on imaging was determined and inter-rater reliability was evaluated in a subgroup of patients (n = 20). Descriptive and comparative analyses were performed. An online questionnaire evaluated the use of abdominal imaging in assessing patients' bowel function in a cross-section of ordering physicians. Results The patient response rate was 19% (96/516). No clinically useful associations between fecal burden and stool form, bowel motion frequency, gastrointestinal symptoms or a diagnosis of constipation was identified. The physician response rate was 35% (33/94). Opportunistic use of data was more common than deliberate use. However, an abdominal radiograph or CT scan had been requested by 42% and 18% of physicians respectively to assess patient's chronic bowel habit. Approximately 30% of physicians believed evidence supported this practice. Conclusions Physicians may use abdominal CT in their assessment of patients' chronic bowel habits. However, objective assessment does not support this practice. Colonic stool burden does not correlate with patient-reported symptoms or a criteria-based diagnosis of constipation.