Benign Prostatic Hyperplasia (BPH): Despite normal prostate imaging, BPH can still be present, especially if the imaging was not comprehensive or if the condition is in its early stages. The symptoms of decreased urinary caliper, urinary frequency, and loss of bladder control are classic for BPH. The lack of improvement with antibiotics suggests the condition is not infectious.

Overactive Bladder (OAB): Characterized by urgency, frequency, and nocturia, with or without urge incontinence. The symptoms of increased urinary frequency and loss of bladder control could align with OAB, especially in the absence of infection.
Urinary Tract Infection (UTI) with Resistant Organisms: Although the patient was treated with ciprofloxacin and fluconazole without improvement, the possibility of a UTI with organisms resistant to these antibiotics cannot be entirely ruled out, especially if the initial diagnosis was based on symptoms alone without a culture.
Diabetes Mellitus: Can cause urinary frequency, urgency, and incontinence due to high blood sugar levels affecting bladder function and possibly leading to a condition known as diabetic cystopathy.

Neurogenic Bladder: Due to diseases affecting the brain, spinal cord, or nerves, which can lead to a loss of bladder control. Conditions such as stroke, multiple sclerosis, or spinal cord injuries must be considered, as missing these could lead to significant morbidity.
Bladder Cancer: Although less likely given the absence of hematuria, bladder cancer can cause irritative symptoms like frequency and urgency. It's crucial not to miss this diagnosis due to its potential for severe outcomes if left untreated.
Spinal Stenosis or Cauda Equina Syndrome: These conditions can cause neurological symptoms including bladder dysfunction. Early recognition is critical to prevent long-term damage.

Interstitial Cystitis: A condition causing bladder pressure, bladder pain, and sometimes pelvic pain. The symptoms can overlap with those presented, but it's less common in men.
Sphincter Dysfunction: Either detrusor-sphincter dyssynergia or intrinsic sphincter deficiency can lead to urinary incontinence and other urinary symptoms. These conditions are less common and often associated with neurological disorders or surgical complications.