P300 A prospective study evaluating the incidence of de novo IBS following diverticulitis

Background

Diverticular disease (DD) is highly prevalent in western countries. Following an episode of uncomplicated diverticulitis (UD), symptoms including left abdominal pain and constipation, without evidence of inflammation may arise known as uncomplicated symptomatic diverticular disease (SUDD). Despite this, many experience symptoms more in keeping with IBS. Questions arise as to whether IBS symptoms are pre-existing and aggravated by diverticulitis, or whether they represent post-diverticulitis IBS (PD-IBS), similar to post-infective IBS (PI-IBS) which occurs in 5-10% of those with “Traveller’s Diarrhoea”. There are no prospective studies linking DD and development of IBS-like symptoms. We aim to distinguish ongoing IBS from de novo IBS and SUDD and aim to establish whether pre-existing IBS is exacerbated by an episode of diverticulitis.

Methods

Data were gathered prospectively on all patients attending the Diverticular Clinic at King’s College Hospital, London. Patients with a defined episode of acute diverticulitis were identified. Patients were questioned on pre-existing IBS, pain location and current gastrointestinal (GI) symptoms using ROME IV criteria. Those with pre-existing IBS were questioned on worsening of symptoms following diverticulitis. Subjects were re-questioned at 3, 6 and 12 months and up to 5years. PD-IBS was diagnosed where de novo IBS symptoms met the ROME IV criteria, being present for at least 6 months.

Results

360 new patients were reviewed between 2012 and 2020. Mean age was 57 years, (28-98). There were 221 females (61%) versus 139 (39%) males. There were 251 with an episode of diverticulitis. of these, 139 reported IBS symptoms for at least 6 months. of those, 85 had pre-existing IBS and 54 (22%) experienced de novo IBS for at least 6 months. In those with pre-existing IBS, 86% reported worsened IBS for at least 6 months (p<0.001). There was a preponderance towards younger age in the de novo-IBS group; mean 54 years versus 57 years in the asymptomatic group (p=0.187), and towards female sex (p=0.098). There were no associations between diverticulitis severity and development of IBS symptoms, DD distribution or pain location. Left colonic disease and left sided pain were most common. There was no significant predominance towards constipation, diarrhoea or alternating bowel habit. Bloating was strongly associated with de novo IBS (p<0.001).

Conclusion

This prospective study reports a 22% incidence of de novo IBS following acute diverticulitis. As seen in PI-IBS, there is a preponderance towards female sex and younger age. PD-IBS appears to be a distinct nosological entity. Recognition of PD-IBS may help inform appropriate patient treatment.