Gabapentin Versus Trospium Chloride for Prevention of a Catheter-related Bladder Discomfort Inside the ICU

Inclusion Criteria: * Both males and females with age 20-65 years * American Society of Anesthesiologists (ASA) physical status class I, II or III. * Patients will undergoing elective spinal surgery and will require catheterization of the urinary bladder. Exclusion Criteria: * known allergy to the study drugs or patient refusal. * Urinary bladder pathology as overactive bladder (frequency more than 3 times in the night or more than 8 times in 24 h), bladder outflow obstruction, urinary tract infection or malignancy * Preoperative neurological bladder and/or bowel involvement secondary to spinal cord compression. * Chronic opioids use for chronic pain, drugs or alcohol abuse * Moderate to severe hepatic disease, renal impairment with creatinine clearance (CrCl) less than 30 ml/minute * Narrow angle glaucoma * Psychiatric diseases * Gastrointestinal obstructive conditions as severe chronic constipation or ileus