Diverticulitis Peaks During Warmer Months : JAMA Surg | Apr 2026

Introduction:

Diverticulitis is a common cause of acute abdominal hospitalization and contributes substantially to healthcare utilization worldwide. While seasonal variation has been recognized in several gastrointestinal and surgical conditions, whether diverticulitis follows a reproducible temporal pattern has remained uncertain. Understanding such trends could provide insight into disease triggers and help guide preventive strategies and healthcare planning.

Problem Statement:

The factors precipitating acute diverticulitis are incompletely understood. If seasonal fluctuations exist, they may point toward modifiable environmental, dietary, microbial, or behavioural influences that contribute to disease onset. Clarifying these patterns could improve both mechanistic understanding and resource allocation.

Summary:

This systematic review evaluated global evidence on seasonal variation in diverticulitis incidence and hospital admissions, encompassing more than one million cases across four continents. The analysis demonstrated a remarkably consistent pattern, with most studies reporting peak rates during summer or autumn and the lowest incidence during winter. Importantly, a reversal of this pattern between the Northern and Southern Hemispheres strongly supports the existence of true seasonality rather than random variation. The magnitude of seasonal fluctuation was substantial, with peak periods showing noticeably higher admission rates than trough periods. Several potential explanations were proposed, including dehydration during warmer weather, seasonal dietary changes, alterations in gut microbiota, immune system modulation, and variations in vitamin D exposure. Notably, while the incidence of diverticulitis varied by season, disease severity did not appear to follow the same pattern, suggesting that environmental factors may influence disease onset rather than progression. These findings provide compelling evidence that diverticulitis is influenced by seasonal factors and highlight the potential role of modifiable environmental and lifestyle exposures. From a clinical perspective, awareness of predictable seasonal peaks may assist healthcare systems in anticipating increased demand. Future prospective studies incorporating patient-level environmental, dietary, and biological data are needed to better define the mechanisms underlying this seasonal phenomenon and identify opportunities for prevention.