Diverticular disease is both very common and largely asymptomatic. It is increasingly prevalent with age. Less than 10% of 40-year-olds have diverticulosis; however, the figure increases to 30–40% by age 60 years and 50–70% by age 80 years. It is more common in industrialised countries and associated with low fibre diets, obesity, sedentary lifestyle and smoking. NSAID use and corticosteroids are quoted to increase complication risk, such as bleeding and perforation. The natural history includes 70–80% of patients with diverticulosis remaining asymptomatic lifelong. Approximately 15–20% of patients eventually become symptomatic, but with uncomplicated diverticulitis that may be managed as an outpatient with bowel rest, analgesia and antibiotics. Some 12–15% of diverticulitis cases, however, will eventually become complicated and require hospital care with administration of intravenous antibiotic therapy and potentially surgical review. That is, overall, about 4–5% of patients with diverticulosis will eventually experience complicated diverticulitis during their lifetime, and of these, 3–5% will experience a diverticular bleed. Diverticulitis has a tendency to recur, and the recurrence rate for acute diverticulitis ranges between 16% and 35%, with roughly 20% of patients experiencing another episode within 5 to 10 years following their initial attack. The risk of future attacks increases if the first episode was complicated or if it occurred in patients under the age of 50 years. The risk increases with each flare-up. After a second episode, the recurrence rate jumps to roughly 55% over a 10-year period. Younger patients (typically under 50) and those with more complicated presentations tend to experience higher recurrence rates. Pips, seeds and nuts are irrelevant to episodic diverticulitis, although they have grown to occupy myth status in this regard. Major complications requiring hospital admission include acute diverticulitis warranting intravenous antibiotic therapy, pain management and bowel rest, abscess development, perforation, fistula development, bowel obstruction and peritonitis. Some acute diverticulitis events may be secondary to micro-perforation, with inflammation developing in and around diverticula. Such cases typically present with left lower quadrant pain, fever, raised inflammatory markers and altered bowel habit. Diverticular bleeding occurs with a ~3–5% lifetime risk and is usually painless, large-volume haematochezia. This is the most common cause of lower GI bleeding in older adults and is confronting for patients. Often, bleeding stops spontaneously (~70–80%), but with a recurrence rate of ~20–40%, which may require radiologically targeted embolisation or surgical intervention. Abscess formation occurs in ~15% of acute diverticulitis cases. Both frank perforation and peritonitis are less common. Other diverticular complications include fistula formation, with a frequency of about ~2–4%. The most common fistula is colovesical, presenting with pneumaturia, recurrent UTIs and faecaluria. Whilst most cases of acute complicated diverticulitis can be managed conservatively without surgery, I like to involve surgeons early in the hospital management of patients. For a deeper dive into this subject, we are joined by colorectal surgeon Asiri Arachchi, who is frequently called for his expert advice and intervention and provides an excellent service for both emergency and elective care across all colorectal pathologies in Southeast Melbourne. Asiri trained in high-volume colorectal units at Monash Health Victoria, Austin Health, North Shore Hospital Auckland and Christchurch Hospital, and is proficient in laparoscopic, open and robotic surgery. Please welcome Asiri to the podcast. References: Dr Asiri Arachchi: caseysurgicalgroup.com.au Colorectal Surgery Australia and New Zealand Charity PubMed Central NIH – Diverticular Disease
