Prevalence of Segmental Colitis Associated With Colic Diverticulosis (SCAD): an Observational Study

Colonic diverticula are common in Western countries, affecting up to 60% of subjects over 70 years of age. In about 80% of patients, colonic diverticula remain asymptomatic (diverticulosis), while approximately 20% of patients may develop abdominal symptoms (symptomatic uncomplicated diverticular disease, SUDD) and, eventually, complications such as bouts of diverticulitis or bleeding.

A small proportion of patients with colonic diverticulosis may develop segmental colitis associated with diverticulosis (SCAD). SCAD is separate clinical disease with specific macroscopic (erythema, friability and ulcerations) and microscopic features characterized by chronic, mucosal inflammation involving the inter-diverticular mucosa (usually sigmoid colon) sparing the proximal colon and rectum colon.

The most common symptoms of SCAD are rectal bleeding, diarrhoea and abdominal pain.

To achieve SCAD diagnosis a correct biopsies sampling is mandatory. It is necessary to take biopsies on the borders of the diverticula and in the apparently normal adjacent mucosa as well as biopsies in both the colon proximal to the diverticular area and the rectum in order to exclude chronic inflammatory bowel disease. The spectrum of histological lesions associated with SCAD is variable, including mild non-specific inflammation and inflammatory bowel disease (IBD)-like changes.

Currently, data regarding prevalence of SCAD are scarce. It has been estimated that in patients with diverticulosis, SCAD prevalence ranged from 0.3-1.3%.

The aim of the present study is to assess prospectively the prevalence of segmental colitis associated with colon diverticulosis (SCAD), in consecutive patients with colic diverticulosis, in a tertiary university centre.