What Causes Pain in the Lower Right Abdomen?

Right lower abdominal pain is a common clinical symptom that can arise from a wide range of conditions—some benign and self-limiting, others requiring urgent medical evaluation. The right lower quadrant (RLQ) of the abdomen houses several key structures, including the appendix, cecum and ascending colon, terminal ileum, right ovary and fallopian tube (in individuals assigned female at birth), and the right ureter. Pain originating in this region therefore warrants careful assessment to determine its underlying cause.

Acute appendicitis remains the most frequently encountered surgical emergency associated with RLQ pain. It typically begins as vague, periumbilical discomfort before localizing to the right lower abdomen, often accompanied by nausea, anorexia, low-grade fever, and worsening pain with movement or coughing. Physical examination may reveal rebound tenderness, guarding, and Rovsing’s sign—pain in the RLQ elicited by palpation of the left lower quadrant.

Other gastrointestinal causes include ileitis (often related to Crohn’s disease), infectious colitis, cecal diverticulitis, or constipation-induced distension. In women of childbearing age, gynecologic etiologies must be considered: ovarian torsion, ectopic pregnancy, tubo-ovarian abscess, or mittelschmerz (mid-cycle ovulation pain). Urinary tract pathology—such as right-sided ureteral stones or pyelonephritis—can also refer pain to this region, frequently presenting with dysuria, urinary frequency, or hematuria.

Less common but clinically significant diagnoses include Meckel’s diverticulitis, epiploic appendagitis, and primary or metastatic malignancies involving the cecum or ileocecal valve. In older adults, ischemic colitis or diverticular disease may manifest atypically in the RLQ.

Because the differential diagnosis spans multiple organ systems and includes time-sensitive conditions, prompt clinical evaluation—including history, physical examination, laboratory testing (e.g., CBC, CRP, urinalysis, pregnancy test), and imaging (ultrasound first-line in young women; CT when indicated)—is essential. Patients with persistent, worsening, or systemic symptoms (e.g., fever >38.5°C, tachycardia, hypotension, or signs of peritoneal irritation) should seek immediate medical attention.