Diverticulitis: Given the patient's age, left quadrant tenderness, and trace blood in urine without other urinary symptoms, diverticulitis is a strong consideration. The absence of fever and changes in bowel habits does not rule out this diagnosis, especially in elderly patients who may present atypically.

Inguinal Hernia: The patient has a known inguinal hernia, and while it's not directly related to the suprapubic tenderness, it could contribute to or exacerbate abdominal discomfort, especially if the hernia is incarcerated or strangulated.
Prostate-Related Issues: With a known enlarged prostate, the patient could be experiencing complications such as prostatitis or a prostate abscess, although the absence of urinary symptoms and fever makes this less likely.
Renal Mass: The patient is under surveillance for a renal mass, which could potentially cause flank or abdominal pain, although the presence of suprapubic tenderness might be less typical for a renal mass.

Abdominal Aortic Aneurysm (AAA) Rupture: Although the aorta is reported as 22mm, which is below the typical threshold for AAA, any abdominal pain in an elderly patient warrants consideration of AAA, especially if there's any possibility of recent growth or if the measurement is questionable.
Mesenteric Ischemia: This condition can present with severe abdominal pain out of proportion to physical examination findings and can be a cause of left quadrant and suprapubic tenderness. It's a medical emergency.
Ovarian Torsion or Other Gynecologic Emergencies: Although less common in post-menopausal women, ovarian torsion or other gynecologic issues could present with acute abdominal pain and should be considered, especially if there's any pelvic mass or tenderness.

Retroperitoneal Hematoma: Could be a cause of abdominal pain and might be related to anticoagulation (if the patient is on any) or trauma, though the latter is not mentioned.
Sigmoid Volvulus: Although more common in elderly patients, the absence of significant changes in bowel habits and the presence of suprapubic tenderness make this less likely.
Epididymitis or Testicular Torsion: These conditions are less common in this age group but could cause severe pain and should be considered, especially if there's any scrotal pain or swelling.