The purpose of this study is to assess the safety and efficacy of intravenous administration Moxifloxacin (BAY 12-8039) compared to intravenous ceftriaxone and metronidazole for the treatment of patients with complicated intra abdominal infections. In view of the fact that intra abdominal infections are typically polymicrobial and are often treated empirically, the selected antibacterial agent must cover the likely spectrum of bacterial pathogens. Combination antibiotics therapy has been widely used with great success.

Inclusion Criteria:

• Hospitalized males or females >/= 18 years of age
• Expected duration of treatment with intravenous antibiotics in hospital is anticipated to be >/= 3 full days but not exceeding 14 days
• Ability to provide written informed consent
• Confirmed or suspected intra abdominal infection through surgical procedure or Radiological evidence. For suspected intra abdominal infection, The patient must be scheduled for a surgical procedure

Exclusion Criteria:

• Known hypersensitivity to fluoroquinolones, or other quinolones, and/or to beta lactams antibiotic drugs, or metronidazole or any of the excipients. History of tendon disease/disorder related to quinolone treatment
• Known congenital or documented acquired QT prolongation; uncorrected hypokalemia; clinically relevant bradycardia; clinically relevant heart failure with reduced left ventricular ejection fraction; previous history of symptomatic arrhythmias. Concomitant use of any of the following drugs, reported to increase the QT interval:
• Known severe end stage liver disease (Child Pugh C)
• Systemic antibacterial therapy for more than 24 h within 7 days of enrollment
• Indwelling peritoneal catheter, Pre existing ascites and presumed spontaneous bacterial peritonitis
• All pancreatic processes including pancreatic sepsis, peripancreatic sepsis, or an intra abdominal infection secondary to pancreatitis
• Traumatic perforation of the upper gastrointestinal tract (stomach, duodenum) or perforated peptic ulcer if duration of perforation is < 24 h or if operated on within 24 h of perforation
• Traumatic perforation of the small or large bowel if duration of perforation is < 12 h or if operated on within 12 h of perforation
• Transmural necrosis of the intestine due to acute embolic, thrombotic, or obstructive occlusions
• Acute cholecystitis with infection confined to the gallbladder unless there is evidence of an abscess or necrotic tissue or purulent exudate surrounding the gallbladder indicating a transition of bacteria and the inflammatory process into the abdominal cavity
• Early acute or suppurative, nonperforated appendicitis unless there is evidence of an abscess or peritoneal fluid containing leukocytes and micro organisms suggestive of regional contamination
• Infections originating from the female genital tract. Perinephric infections
• Severe, life threatening disease with a life expectancy of < 48 h or APS and APACHE scores of > 35, Known rapidly fatal underlying disease (death expected within 6 months)
• Neutropenia (neutrophil count < 1,000/microliter) caused by immunosuppressive therapy or malignancy
• Patients known to have AIDS or HIV seropositives who are receiving HAART