Diverticular Disease

Many adults in Singapore experience occasional abdominal discomfort or changes in bowel habits at some point in life. While these symptoms are often attributed to stress or diet, they can sometimes signal diverticular disease, which is a condition involving anatomical changes in the large intestine that, if left unrecognised, can progress to inflammation or complications.

In Singapore, diverticular disease has become more common over recent decades. Some studies estimate that up to 30% of adults aged 50 years or older have diverticula (small pouches) detectable on imaging or colonoscopy, with prevalence rising to over 60% in adults aged 70 years or older. Although most people with diverticula never develop symptoms, a significant minority experience discomfort or inflammation that benefits from medical assessment.

What is diverticular disease?

Diverticular disease refers to a condition in which tiny pouches, called diverticula, develop in the muscular wall of the large intestine. These pouches form when inner layers of the bowel wall push outward through weak spots in the outer muscle layer, often in response to prolonged internal pressure.

When colon diverticula are present without symptoms, the condition is called diverticulosis. Many people may have diverticulosis for years without knowing it and it is often discovered incidentally during a colonoscopy or imaging.

When one or more diverticula become inflamed, irritated or infected, the condition is termed diverticulitis. This inflammatory form can cause pain, fever and more serious complications if left untreated.

Unlike functional disorders that affect only bowel movement, diverticular disease involves structural changes in the colon wall and may have consequences that require medical or surgical intervention.

Diverticular Disease vs. Irritable Bowel Syndrome (IBS)

Diverticular disease and Irritable Bowel Syndrome (IBS) can both cause abdominal discomfort and bowel habit changes, but they are fundamentally different.

• Diverticular Disease – involves physical pouch formation in the colon and, in its inflammatory form, can lead to infection, abscesses, bleeding or bowel perforation. Its symptoms often stem from structural changes and inflammation.
• Irritable Bowel Syndrome (IBS) – affects the way the gut functions, without visible inflammation or damage to the bowel wall. IBS symptoms are typically chronic yet benign with respect to tissue integrity.

This difference matters because diverticular disease, particularly when inflamed, may require antibiotics, procedural intervention or surgery, whereas IBS is managed with symptom-focused strategies.

What causes diverticular disease?

The disease develops through a combination of structural changes in the colon wall and chronic internal pressure. These mechanisms can lead to the formation of diverticula and influence whether they become symptomatic, such as:

• Structural weakening of the colon wall – over time, areas of the colon wall can become thinner or weaker, especially with ageing. This weakness allows the inner layers to bulge outward, forming pouches.
• Chronic pressure inside the colon – long-standing constipation or hard stools increase pressure within the colon each time a bowel movement is attempted. Elevated pressure promotes the formation of diverticula at weak points.
• Low-fibre diets – diets low in fibre, common in typical Westernised eating patterns, may result in harder, smaller stools that are more difficult to pass. Smaller, harder stools require stronger muscular contractions, increasing intraluminal pressure and predisposing to diverticula formation.
• Lifestyle and gut motility factors – sedentary habits, obesity and disrupted intestinal motility may contribute to the environment in which diverticula forms and become symptomatic.

What are the symptoms of diverticular disease?

Many people with diverticular disease have no symptoms. When symptoms develop, they may vary depending on whether diverticula are complicated or uncomplicated.

Some of the common symptoms include:

• Bloating or abdominal distension
• Lower abdominal pain, often on the left side, cramping or persistent
• Changes in bowel habits, often alternating between constipation and diarrhoea
• Tenderness during bowel movements
• Nausea or mild discomfort

When inflammation develops, symptoms may include:

• Sudden severe abdominal pain
• Fever and chills
• Nausea and vomiting
• Significant tenderness over part of the abdomen

When is it considered a medical emergency?

Contact your colorectal specialist immediately if you have:

• Sudden, severe abdominal pain
• Rectal bleeding (especially if significant or painless)
• A rigid or very tender abdomen
• High fever with severe abdominal pain. This can signal perforation or abscess, which are emergencies

Who is at risk of diverticular disease?

Although diverticular disease is common in Singapore, several factors increase the risk of developing the disease. This includes:

• Ageing – the risk increases significantly with age as the colon wall gradually loses strength and elasticity over time. Areas of the intestinal wall may become thinner and more susceptible to bulging outward when exposed to internal pressure.
• Low fibre diet – a diet low in fibre results in smaller, firmer stools that move more slowly through the colon. When stool is harder to pass, the colon muscles must contract more forcefully to propel it forward. These stronger contractions increase intraluminal pressure, which can cause weak areas of the colon wall to protrude outward and form diverticula.
• Chronic constipation and straining – repeated straining during bowel movements increases pressure inside the colon. Over time, this persistent pressure can push the inner lining of the bowel through weak spots in the muscle layer, leading to the development of diverticular pouches.
• Medications – long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) may irritate the lining of the digestive tract and increase the risk of inflammation, bleeding or perforation in individuals with diverticula. These medications may also interfere with the protective mechanisms of the intestinal lining.
• Sedentary lifestyle – low levels of physical activity can slow intestinal movement and contribute to constipation. Reduced bowel motility allows stool to remain in the colon for longer periods, thereby increasing intraluminal pressure and promoting diverticula formation.
• Obesity – excess body weight is associated with increased abdominal pressure and changes in gut motility. Studies have also shown that obesity may contribute to low-grade inflammation within the body, which can increase the risk of diverticulitis and other complications once diverticula are present.
• Smoking – smoking may affect blood circulation to the digestive tract and impair the normal function of the intestinal wall. This can weaken the colon's structural integrity and increase the risk of inflammation or complications associated with diverticular disease.

What are the possible complications of diverticular disease?

Without medical attention, diverticular disease may lead to:

• Diverticulitis  – inflammation or infection of diverticula
• Abscess formation – pus collects near the inflamed pouches
• Perforation – a rupture in the colon wall leading to leakage of intestinal contents
• Bowel obstruction – scar tissue or inflammation blocks stool flow
• Bleeding (diverticular haemorrhage) – sudden, painless rectal bleeding from ruptured vessels

How is diverticular disease diagnosed in Singapore?

Assessment usually begins with a detailed clinical review to understand the patient’s symptoms, medical history and potential risk factors. Dr Aaron Poh may then recommend several investigations to confirm the diagnosis and assess for inflammation or complications.

Diagnostic evaluation may include:

• Medical history – our doctor will ask about the pattern and duration of symptoms, including abdominal pain, bowel habit changes, fever or rectal bleeding. Information about diet, medications and prior abdominal conditions may also help identify potential contributing factors.
• Physical examination – a clinical examination of the abdomen allows our doctor to assess for tenderness, abdominal distension or localised pain that may suggest inflammation in the colon.
• Blood tests – blood tests may be performed to check for signs of infection or inflammation, such as elevated white blood cell counts or inflammatory markers.
• Stool tests – stool analysis may be recommended to rule out bacterial or parasitic infections that could cause similar symptoms.
• Computed Tomography (CT) scan of the abdomen – CT imaging is one of the most useful tools for diagnosing diverticular disease. It can identify colonic diverticula and detect complications, including inflammation, abscess formation, bowel wall thickening, or perforation.
• Colonoscopy – a colonoscopy allows direct visualisation of the colon lining and confirms the presence of diverticula. This procedure is typically performed after acute inflammation has resolved, as it helps evaluate the extent of diverticular disease and rule out other conditions such as colorectal cancer.

How is diverticular disease treated in Singapore?

The management of diverticular disease focuses on relieving symptoms, treating inflammation when it occurs and reducing the risk of future complications. Management strategies may include the following:

Lifestyle and dietary measures

For individuals with diverticulosis or mild symptoms, lifestyle adjustments help reduce pressure within the colon and support healthy bowel function.

• High-fibre diet – increasing fibre intake helps produce larger, softer stools that move more easily through the colon. This reduces the need for strong muscular contractions during bowel movements, lowering the internal pressure that contributes to diverticula formation.
• Adequate hydration – drinking sufficient fluids allows fibre to absorb water and soften stool consistency. Softer stools pass through the intestine more easily, reducing straining during bowel movements.
• Regular physical activity – exercise helps stimulate normal bowel motility and promotes regular bowel movements. Improved intestinal motility reduces stool stagnation and decreases intracolonic pressure.

Medical treatment for diverticulitis

When diverticula become inflamed or infected, bowel inflammation treatment is often required to control the inflammatory process and prevent complications.

• Antibiotic therapy – antibiotics are used when bacterial infection is suspected during episodes of diverticulitis. These medications help eliminate infection and reduce inflammation within the affected segment of the colon.
• Pain relief and anti-inflammatory medication – appropriate medications may be prescribed to relieve abdominal discomfort while avoiding drugs that could worsen irritation of the bowel.
• Temporary bowel rest and dietary modification – during acute inflammation, a clear liquid or low-residue diet may be recommended for a short period. This reduces the workload on the colon and allows the inflamed tissue to heal.

Interventional and surgical treatment

Procedural or surgical management may be considered if complications develop or recurrent diverticulitis occurs.

• Abscess drainage – if infection leads to the formation of an abscess, a drainage procedure may be performed to remove the infected fluid and prevent the infection from spreading.
• Colon resection – in cases of severe, recurrent or complicated diverticulitis, the affected portion of the colon may be surgically removed. The remaining healthy segments of the bowel are then reconnected to restore normal intestinal function.
• Minimally invasive surgery – many colorectal procedures can be performed using laparoscopic techniques. These involve smaller incisions and may allow for faster recovery and reduced postoperative discomfort compared with traditional open surgery.

How a Colorectal Specialist can help

A colorectal specialist can help by carefully assessing your symptoms and recommending appropriate investigations when needed. Diverticular disease can present differently across individuals and many experience significant improvement with appropriate evaluation and management.

If you have been experiencing persistent abdominal discomfort, changes in bowel habits or rectal bleeding, seeking medical advice can help clarify the cause and ensure that appropriate care is provided. Early intervention enables effective symptom management and reduces the risk of future complications.

Frequently Asked Questions