Comparison of Clinical Characteristics and Long-term Prognosis of Focal Hypoganglionosis With Adult-onset Megacolon and Chronic Intestinal Pseudo-obstruction.

Background/Aims: Focal hypoganglionosis with adult-onset megacolon (FHAM) is marked by colon dilation proximal to a narrowed segment, with unaffected small bowel motility. Despite similar initial symptoms, FHAM may be more amenable to surgical intervention without recurrence, unlike chronic intestinal pseudo-obstruction (CIPO). The long-term outcomes of FHAM remain underexplored, prompting a comparison of its clinical features and prognosis with CIPO. Methods: We conducted a retrospective analysis of patients presenting with chronic constipation and megacolon, prospectively recruited between January 2017 and December 2023. Within this cohort, 87 patients were diagnosed with FHAM and 13 with CIPO, all of whom were included in the study. The median follow-up period was 3.0 years for patients with FHAM and 2.8 years for those with CIPO. Results: The proportion of females was greater in both groups (FHAM, 67.8%; CIPO, 53.8%). The median age at diagnosis was similar between the groups (FHAM, 54.5 years; CIPO, 45.3 years). Surgery was performed in 46.0% of patients with FHAM and 69.2% of those with CIPO. Unplanned postoperative hospitalizations and the need for reoperation due to disease recurrence were notably lower in patients with FHAM. None of the patients with FHAM required long-term total parenteral nutrition, in contrast to 46.2% of patients with CIPO. Significant inter-group differences were observed in body mass index at the last follow-up. Conclusions: Patients with FHAM exhibit a more favorable long-term prognosis and lower postoperative recurrence rates than patients with CIPO. This study underscores the importance of differentiating between these conditions and precisely selecting surgical candidates.