Left Mid Quadrant Abdominal Pain: Causes and Management

Most Common Causes

The American College of Radiology states that acute colonic diverticulitis of the sigmoid or descending colon is the most common cause of left-sided abdominal pain in adults, with prevalence rising 50% between 2000-2007 1, 2
The differential diagnosis for left mid quadrant pain includes gastrointestinal causes, such as diverticulitis, colitis, inflammatory bowel disease, epiploic appendagitis, bowel obstruction, fecal impaction, and perforated colon cancer, as recommended by the American College of Radiology 1, 2

The American College of Radiology recommends ordering CT abdomen and pelvis with IV contrast immediately, as it is the single most accurate test with 98% diagnostic accuracy and is rated 8/9 (usually appropriate) 3
CT with IV contrast is essential to detect complications, such as abscess, perforation, or fistula, that determine whether to admit or send the patient home, as stated by the American College of Radiology 1, 3

The American College of Radiology recommends immediately sending patients to the emergency department if they present with fever, left-sided pain, and elevated white blood cell count, which is a classic triad for diverticulitis, although it is only present in 25% of cases 3

The American College of Radiology recommends conservative management without antibiotics for immunocompetent patients with uncomplicated diverticulitis, while immunocompromised or elderly patients should receive antibiotics for a maximum of 7 days 3
For complicated diverticulitis with a small abscess, antibiotics alone for 7 days without drainage are recommended, while percutaneous CT-guided drainage plus antibiotics for 4 days are recommended for large abscesses 3

The American College of Radiology recommends repeat imaging if fever and leukocytosis persist beyond 48-72 hours despite appropriate treatment, or if clinical deterioration occurs 4
Outpatient management requires the ability to tolerate oral intake, normal or near-normal bowel movements, no peritoneal signs, and reliable follow-up, as stated by the American College of Radiology 3

The American College of Radiology recommends a contrast‑enhanced CT of the abdomen and pelvis as the first‑line imaging study for any patient with left lower‑quadrant pain; this recommendation is rated 8 / 9 (usually appropriate) and the modality has a reported 98 % diagnostic accuracy for identifying life‑threatening conditions【5】.

Acute diverticulitis is the most common cause of left lower‑quadrant pain in adults, surpassing constipation, and its prevalence increased by approximately 50 % between 2000 and 2007【5】.

The CT‑based differential for left lower‑quadrant pain includes colitis, inflammatory bowel disease, bowel obstruction, perforated colon cancer, pyelonephritis, and urolithiasis, all of which can present with overlapping clinical features【5】.