• To compare the microbiological efficacy of tigecycline to ceftriaxone plus metronidazole in the microbiologically evaluable population [ Time Frame: 10-21 days after the last dose of test article. ] [ Designated as safety issue: No ]
• To evaluate in vitro susceptibility data on tigecycline for a range of pathogenic bacteria that cause cIAI [ Time Frame: 10-21 days after the last dose of test article. ] [ Designated as safety issue: No ]
• To compare health care utilization between treatment groups [ Time Frame: 10-21 days after the last dose of test article. ] [ Designated as safety issue: No ]

• To compare the microbiological efficacy of tigecycline to ceftriaxone plus metronidazole in the microbiologically evaluable population
• To evaluate in vitro susceptibility data on tigecycline for a range of pathogenic bacteria that cause cIAI
• To compare health care utilization between treatment groups

This is a study of the safety and efficacy of tigecycline to ceftriaxone sodium plus metronidazole in hospitalized subjects with cIAI. Subjects will be followed for efficacy through the test-of-cure assessment. Safety evaluations will occur through the treatment and post-treatment periods and continue through resolution or stability of the adverse event(s).

• Appendicitis
• Cholecystitis
• Diverticulitis
• Intra-Abdominal Abscess
• Intra-abdominal Infection
• Peritonitis

• Drug: tigecycline
• Drug: ceftriaxone plus metronidazole

Inclusion Criteria:

• Clinical diagnosis of complicated intra-abdominal infection that requires surgery within 24 hours.
• Fever plus other symptoms such as nausea, vomiting, abdominal pain.

Exclusion Criteria:

• Cancer
• Medicines that suppress the immune system
• Dialysis