Diverticulitis

Abdominal pain that develops suddenly and persists for several days can be concerning, particularly when it is accompanied by fever, digestive discomfort or changes in bowel habits. While many digestive conditions can cause these symptoms, one possible cause is diverticulitis.

In Singapore and other developed countries, diverticular disease has become increasingly common due to ageing populations and dietary patterns low in fibre. Studies suggest that diverticula may be present in over 50% of adults above the age of 60, although only a portion of these individuals develop diverticulitis.

What is diverticulitis?

Diverticulitis is an inflammatory condition affecting the large intestine (colon). It occurs when one or more diverticula, which are small sac-like pouches that protrude from the colon wall, become inflamed or infected.

These pouches usually form in areas where the intestinal wall is slightly weaker. When inflammation develops, the surrounding tissues may become swollen and irritated, causing pain and digestive symptoms.

The condition most commonly affects the sigmoid colon in the western population, which is located in the lower left side of the abdomen. Inflammation in this region often explains why many patients experience pain in the lower left abdomen. In contrast, the Asian population has an equal prevalence of left and right sided colonic diverticuli, and this can result in abdominal pain of the right or left side.

While mild cases may resolve with conservative treatment, more severe episodes can lead to complications such as abscess formation, bowel obstruction or perforation.

What causes diverticulitis?

The condition typically develops when a diverticulum becomes blocked or irritated. This can allow bacteria to multiply within the pouch, triggering inflammation and infection.

Several factors may contribute to this process:

• Stool trapping within a diverticulum – small pieces of stool may become lodged inside the pouch, leading to bacterial growth and irritation.
• Increased pressure within the colon – straining during bowel movements may place stress on the diverticular wall.
• Changes in gut bacteria – alterations in intestinal microbiota may influence inflammation within diverticula.
• Reduced bowel motility – slower movement of stool through the colon can increase pressure and irritation.
• Dietary factors – long-term low fibre intake may contribute to the development of diverticula and increase the risk of inflammation.

Often, diverticulitis develops through a combination of these factors rather than a single cause.

What is the difference between diverticulitis and diverticulosis?

Diverticulitis is often confused with diverticulosis, but the two conditions describe different stages of the same underlying process.

Diverticulosis refers to the presence of diverticula in the colon without inflammation. Many individuals with diverticulosis have no symptoms and may only discover the condition during a routine colonoscopy or imaging.

A helpful analogy: diverticulosis is like having potholes in a road: they exist, but may cause no trouble. Diverticulitis is when something gets stuck in one of those potholes and causes a real problem. While diverticulosis is relatively common, only about 10 to 25% of individuals with diverticula develop diverticulitis at some point in their lives.

What are the symptoms of diverticulitis?

Diverticulitis can produce a range of digestive symptoms, which may vary in severity depending on the extent of inflammation. Some of the common symptoms include:

• Persistent lower abdominal pain, typically on the left side
• Fever or chills
• Nausea or vomiting
• Bloating or abdominal tenderness
• Constipation or, less commonly, diarrhoea
• Changes in bowel habits
  

The abdominal pain associated with diverticulitis often develops gradually and may worsen over several days. In more severe cases, symptoms may be accompanied by signs of infection or complications, such as severe abdominal pain or difficulty passing stool or gas.

Who is at risk of developing diverticulitis?

Although diverticulitis is a common condition, there are several factors that can increase the likelihood of diverticulitis occurring. These include:

• Ageing – the prevalence of diverticula increases with age, making diverticulitis more common in adults over 50 years old.
• Certain medications – regular use of non-steroidal anti-inflammatory drugs (NSAIDs), steroids or immunosuppressive medications may increase susceptibility to inflammation.
• Low fibre diets – insufficient fibre intake can contribute to harder stools and increased pressure in the colon.
• Obesity – higher body weight has been associated with increased risk of diverticulitis and its complications.
• Sedentary lifestyle – limited physical activity may affect bowel motility.
• Smoking – smoking has been linked to a higher risk of diverticular complications.

How is diverticulitis diagnosed in Singapore?

Dr Aaron Poh often diagnose diverticulitis by confirming inflammation and ruling out other conditions that may cause similar symptoms.

The assessment may include:

• Medical history and physical examination – our doctor evaluates the pattern of abdominal pain, fever, digestive symptoms and risk factors.
• Blood tests – these tests help detect signs of infection or inflammation.
• Computed Tomography (CT) scan of the abdomen – computed tomography is one of the most reliable ways to confirm diverticulitis and assess its severity.
• Colonoscopy – this may be performed after inflammation has resolved to evaluate the colon and exclude other conditions such as polyps or tumours.

How is diverticulitis treated in Singapore?

Treatment for colon inflammation depends on the severity of inflammation and whether complications are present.

Mild cases are often managed with conservative treatment, including:

• Antibiotic therapy – antibiotics are commonly prescribed when bacterial infection is suspected. These medications help control inflammation within the diverticulum and prevent the infection from spreading to surrounding tissues. Depending on the severity of symptoms, antibiotics may be taken orally at home or administered intravenously in a hospital.
• Temporary dietary modification – during the acute phase of diverticulitis, the colon may require time to recover. Patients are sometimes advised to begin with a clear or low-fibre diet to minimise bowel activity and irritation. As symptoms improve, fibre is gradually reintroduced to support healthier bowel function and reduce future flare-ups.
• Pain and symptom control – pain relief medications and supportive care are used to manage abdominal discomfort, fever or nausea associated with inflammation. Treatment is carefully selected to avoid medications that may worsen gastrointestinal irritation.

Meanwhile, more severe cases may require:

• Abscess drainage – in some cases, inflammation can lead to the formation of an abscess, which is a localised collection of infection near the colon. When this occurs, drainage may be required. This is often performed using imaging guidance, allowing the infection to be safely drained without open surgery.
• Surgical treatment – surgery may be considered if diverticulitis becomes recurrent, causes bowel obstruction or leads to complications such as perforation or persistent infection. The procedure typically involves removing the affected portion of the colon and reconnecting the healthy sections to restore normal bowel function.

How a Colorectal Specialist can help

Diverticulitis can present with symptoms that overlap with other abdominal conditions, including appendicitis, inflammatory bowel disease (IBD) and bowel infections. Accurate diagnosis is therefore essential before treatment decisions are made.

A colorectal specialist evaluates the pattern of symptoms, reviews imaging findings and determines whether the inflammation is mild, complicated or part of a recurring pattern. This helps guide the most appropriate treatment plan while reducing the risk of unnecessary procedures.

For individuals who experience repeated episodes or complications, specialist care also focuses on long-term strategies to stabilise bowel health and prevent future attacks. Book an appointment for a personalised assessment and guidance on managing diverticulitis and protecting your long-term colon health.

Frequently Asked Questions