Bowel movement alterations predict the severity of diverticular disease and the risk of acute diverticulitis: a prospective, international study

Background/aims: Patients with diverticular disease (DD) frequently have abnormal bowel movements. However, it is unknown whether the entity of these alterations is associated with the severity of DD. We aimed to assess bowel habits and their relationship with the severity of DD according to Diverticular Inflammation and Complication Assessment (DICA) classification, Combined Overview on Diverticular Assessment (CODA) score, and fecal calprotectin (FC). Methods: An international, multicenter, prospective cohort study was conducted in 43 centers. A 10-point visual analog scale (VAS) was used to assess the severity of constipation and diarrhea. The association of constipation and diarrhea with DICA classification, CODA score, and basal FC was tested using non-parametric tests. Survival methods for censored observations were applied to test the association of constipation and diarrhea with the incidence of acute diverticulitis over a 3-year follow-up. Results: Of 871 patients with DD were included in the study. Of these, 208 (23.9%) and 199 (22.9%) reported a VAS score for constipation and diarrhea at least 3 at baseline, respectively. Higher constipation and diarrhea scores were associated with increasing DICA classification, CODA score and basal FC (P< 0.001). Constipation and diarrhea scores were independently associated with an increased hazard of developing acute diverticulitis (hazard ratio [HR]constipation = 1.15 per 1-VAS point increase, 95% confidence interval [CI], 1.04-1.27; P=0.004; and HRdiarrhea =1.14; 95% CI, 1.03-1.26; P=0.014, respectively). Conclusions: In newly diagnosed patients with DD, higher endoscopic and combined scores of DD severity were associated with higher scores of constipation and diarrhea at baseline. Both constipation and diarrhea were independent prognostic factors of acute diverticulitis.