Is diarrhea associated with diverticulitis, especially in older adults with a history of diverticulosis?

Is Diarrhea Associated with Diverticulitis?

Yes, diarrhea can be associated with diverticulitis, though it is not the most common presenting symptom—abdominal pain remains the hallmark presentation. However, bowel movement alterations including diarrhea are clinically significant and predict both disease severity and risk of acute diverticulitis 1, 2.

Clinical Presentation of Diverticulitis

The typical presentation of acute diverticulitis centers on abdominal pain, but bowel habit changes are common:

• Abdominal pain (usually left lower quadrant in Western populations) is the most common presenting symptom 1
• Change in bowel habits is a recognized presenting sign, which can manifest as either constipation or diarrhea 1
• Other symptoms include fever, nausea without vomiting, and elevated inflammatory markers 1

Important Caveat in Elderly Patients

The clinical presentation is significantly more nuanced in elderly patients, making diarrhea and other atypical presentations more relevant diagnostically:

• Only 50% of elderly patients (>65 years) with acute left colonic diverticulitis present with lower quadrant abdominal pain 1, 3
• Only 17% have fever 1, 3
• 43% do not have leukocytosis 1, 3
• A higher proportion of older patients present with diverticular bleeding 1

Diarrhea as a Prognostic Indicator

Recent evidence demonstrates that diarrhea severity independently predicts both disease severity and future complications:

• Higher diarrhea scores (measured on a 10-point visual analog scale) are associated with increasing DICA classification, CODA score, and elevated fecal calprotectin 2
• Diarrhea is an independent prognostic factor for developing acute diverticulitis (hazard ratio 1.14 per 1-point VAS increase, 95% CI 1.03-1.26, P=0.014) 2
• 22.9% of patients with diverticular disease report significant diarrhea (VAS score ≥3) at baseline 2

Specific Diverticular Conditions Associated with Diarrhea

Segmental Colitis Associated with Diverticulosis (SCAD)

• SCAD is a distinct diagnosis characterized by diverticular colitis that spares the rectum and is likely on the spectrum of inflammatory bowel diseases 1
• SCAD most often presents with rectal bleeding but can present with diarrhea 4
• This condition develops almost exclusively in older adults and occurs mainly in the sigmoid colon 4

Diverticular Abscess

• Although rarely reported, abdominal abscesses due to colonic diverticulitis may present as refractory chronic diarrhea 5
• One case report documented a 72-year-old woman with a one-month history of non-bloody diarrhea, abdominal pain, and low-grade fever from a large pelvic abscess secondary to perforated diverticulitis 5

Clinical Implications for Diagnosis

Do not rely on clinical signs, symptoms, and laboratory tests alone in elderly patients:

• Elderly patients presenting with abdominal pain or altered bowel habits (including diarrhea) should undergo CT imaging with IV contrast regardless of leukocyte or CRP values 1, 3
• Typical signs of abdominal sepsis may be masked in elderly patients, leading to delayed diagnosis and high mortality 3
• Pain out of proportion to physical examination findings demands immediate imaging, particularly in elderly patients with cardiovascular disease 3

Differential Diagnosis Considerations

When a patient presents with diarrhea and suspected diverticulitis, consider:

• Irritable bowel syndrome may be clinically indistinguishable from diverticulitis 6
• Crohn's disease of the colon is less easily differentiated, especially in patients over 40 where the two diseases often coexist 6
• Ischemic colitis usually shows characteristic features that distinguish it from diverticulitis 6
• Alternative diagnoses should be excluded with both imaging and lower endoscopy in patients with a history of diverticulitis and chronic symptoms 1

Key Clinical Pitfall

The absence of typical symptoms (including the presence of diarrhea instead of constipation) should not reassure you in elderly patients—they frequently present atypically and have higher mortality despite less dramatic presentations 1, 3.