A 73-year-old woman presents with lower abdominal pain and foul-smelling vaginal discharge, with pain on intercourse. Which diagnosis is most likely?

• A. Pelvic inflammatory disease.
• B. Inflammatory bowel disease.
• C. Urinary tract infection.
• D. Nephrolithiasis.

Answer: (A)

Pelvic inflammatory disease is suggested when a patient has lower abdominal pain along with vaginal discharge that has a foul odor and pain with intercourse. This combination points to an infection involving the upper female genital tract, typically starting with cervicitis and progressing to endometritis or salpingitis. The discharge reflects an infectious process in the vaginal/cervical area, and the pelvic pain with dyspareunia indicates deeper, pelvic involvement beyond the lower urinary or bowel tract.

Inflammatory bowel disease would mainly cause gastrointestinal symptoms like abdominal pain with diarrhea or blood in stool, not a foul-smelling vaginal discharge. A urinary tract infection would produce dysuria, urinary frequency, urgency, and sometimes suprapubic pain, but not the characteristic vaginal discharge. Nephrolithiasis presents with sudden, severe flank or groin pain and often hematuria, not vaginal discharge or pain with intercourse.

So the presentation aligns best with a pelvic infection affecting the upper genital tract, making pelvic inflammatory disease the most likely diagnosis.