Anal Cancer

Colonic diverticula are acquired mucosal and submucosal herniations through points of weakness where vasa recta penetrate the muscular wall. Disease is predominantly sigmoid in Western populations, although right sided disease is more prevalent in some populations.

Diverticulosis refers to the anatomical presence of diverticula.

Diverticular disease implies clinically significant symptoms or complications.

Complications include acute diverticulitis, abscess, fistula, stricture, obstruction, bleeding and perforation.

Uncomplicated diverticulosis is usually asymptomatic.

Symptomatic uncomplicated diverticular disease may produce recurrent left lower abdominal discomfort and altered bowel habit without objective acute inflammation.

Diverticular bleeding is typically sudden, painless and can be substantial.

Diverticulitis causes a distinct acute inflammatory syndrome and should not be diagnosed solely because diverticula are present on imaging.

Colonoscopy: confirms diverticulosis and excludes other colonic disease when clinically appropriate, but should not be performed during severe acute diverticulitis because instrumentation increases perforation risk.

CT abdomen with IV contrast: use when acute inflammatory or obstructive complications are suspected.

Asymptomatic diverticulosis requires no operative treatment.

Encourage a generally high quality fibre containing diet when tolerated. Routine avoidance of nuts, seeds or popcorn is unnecessary.

Do not prescribe elective sigmoid colectomy solely because a patient has experienced an arbitrary number of uncomplicated diverticulitis episodes. Surgery should be individualised according to severity, recurrence burden, persistent symptoms, immune status and operative risk.

Definite structural complications such as fistula, obstruction or stricture are strong indications for elective or semielective sigmoid resection.

When elective surgery is undertaken, remove the entire diseased sigmoid segment and construct the distal anastomosis to healthy rectum rather than leaving residual distal sigmoid, which increases recurrence risk. Proximal diverticula do not need to be removed simply because they are present.