Diverticular Disease

Diverticular disease encompasses complications arising from diverticulosis, a benign condition characterised by the formation of pouches (diverticula) from the weak spots in the wall of the large intestine. This disease spectrum includes diverticulitis, symptomatic uncomplicated diverticular disease (SUDD), and segmental colitis associated with diverticulosis (SCAD). Common symptoms include abdominal pain, changes in bowel habits, nausea, and vomiting.

Endoscopic image of diverticulosis (showing two diverticula)

Signs and Symptoms

The primary signs and symptoms of diverticular disease stem from inflammation and irritation of colonic tissues. Patients commonly report abdominal pain, typically localised in the left lower quadrant, though individuals of Asian descent may experience right-sided pain. Other symptoms can include diarrhoea, constipation, nausea, vomiting, fever, and rectal bleeding. Distinctions exist within the disease spectrum: diverticulitis is often associated with systemic symptoms such as fever and elevated white blood cell count, while SUDD and SCAD generally lack these systemic indicators.

Causes

Diverticulitis

Diverticulitis arises from either trauma or reduced blood flow (ischaemia) to the existing diverticula in the colon. The traumatic theory suggests that a fecalith (hardened faecal matter) can become trapped, leading to local inflammation and bacterial overgrowth, potentially resulting in bowel perforation. The ischaemic theory posits that prolonged colonic contractions compress blood vessels, leading to ischaemia, inflammation, and perforation.

Symptomatic Uncomplicated Diverticular Disease (SUDD)

SUDD is thought to result from sustained colonic contractions leading to mucosal ischaemia within the diverticulum. Unlike diverticulitis, SUDD presents solely with abdominal pain and bowel habit changes, without systemic symptoms like fever or elevated inflammatory markers.

Segmental Colitis Associated with Diverticulosis (SCAD)

SCAD, or diverticular colitis, involves mucosal inflammation in a colonic segment with diverticulosis, usually confined to the sigmoid colon. The cause is multifactorial, potentially involving colonic ischaemia, mucosal prolapse, faecal stasis, and microbiome disturbances, which collectively lead to inflammation.

Risk Factors

Several risk factors contribute to the development and severity of diverticular disease, including advanced age, structural weaknesses in the colonic wall, dietary fibre intake, NSAID and aspirin use, genetics, and vitamin D levels. While a low-fibre diet was traditionally associated with diverticular disease, recent studies suggest that increased fibre intake primarily reduces complications.

Diagnosis

Diverticulitis

Diagnosis of diverticulitis typically involves assessing symptoms such as left lower abdominal tenderness, fever, and changes in bowel habits. Laboratory tests often reveal elevated white blood cell counts and inflammatory markers. Imaging, particularly computed tomography (CT), is very important for diagnosing diverticulitis and assessing complications.

Symptomatic Uncomplicated Diverticular Disease (SUDD)

SUDD presents with chronic left lower abdominal pain and bowel habit changes, primarily diarrhoea. The absence of systemic inflammation (e.g., fever, elevated white blood cell count) differentiates SUDD from other conditions. Faecal calprotectin levels can correlate with symptom severity.

Segmental Colitis Associated with Diverticulosis (SCAD)

SCAD presents with rectal bleeding and possibly bowel habit changes, typically without fever. Endoscopic evaluation and biopsy are necessary for diagnosis, revealing inflammation confined to segments with diverticula. Laboratory tests usually show normal white blood cell counts and negative serological markers, distinguishing SCAD from other inflammatory bowel diseases.

Treatment

Diverticulitis

Uncomplicated diverticulitis is treated conservatively with bowel rest, and antibiotics are generally not required, except in immunocompromised patients. Complicated diverticulitis may require antibiotics and surgical interventions for abscess drainage or fistula repair. Pain is managed with antispasmodics or acetaminophen, avoiding NSAIDs. Colonoscopy is recommended post-recovery to confirm the diagnosis and rule out other conditions like cancer.

Symptomatic Uncomplicated Diverticular Disease (SUDD)

There is no universally effective treatment for SUDD. Mesalamine and rifaximin may alleviate symptoms and prevent acute diverticulitis, and probiotics could be beneficial, although evidence is limited.

Segmental Colitis Associated with Diverticulosis (SCAD)

SCAD is typically self-limiting, but ongoing or recurrent cases may require antibiotics, mesalamine, or corticosteroids for management.

Self-assessment MCQs (single best answer)

Which of the following is NOT a part of the diverticular disease spectrum?

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What is the primary symptom of diverticular disease that patients typically report?

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Which theory suggests that diverticulitis results from prolonged colonic contractions compressing blood vessels?

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Which condition is characterised by abdominal pain and changes in bowel habits, but lacks systemic symptoms such as fever?

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Which diagnostic tool is very important for assessing diverticulitis and its complications?

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What is the initial treatment approach for uncomplicated diverticulitis?

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Which of the following is a common risk factor for the development of diverticular disease?

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Which of the following treatments is NOT typically recommended for managing pain in diverticulitis?

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Which condition is characterised by inflammation confined to colonic segments with diverticulosis, usually in the sigmoid colon?

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What role does dietary fibre play in the context of diverticular disease according to recent studies?

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