Community acquired intra-abdominal infection of mild to moderate severity

Cefoperazone-sulbactam

Piperacillin-tazobactam

Community acquired intra-abdominal infection with high severity

Imipenem or meropenem

Healthcare associated intra-abdominal  infections

Imipenem/ Meropenem + vancomycin

Colistin, Tigecyline

-Based on the findings of intra-operative cultures cover for Enterococcus may either be stopped or changed. If multi-drug resistant organism is isolated, based on susceptibility patterns, colistin, tigecyline may be used.
-Echinocandins or fluconazole if risk factors for Candida.

Infected pancreatic necrosis, pancreatic abscess

Imipenem-cilastatin
and vancomycin

Therapy to be adjusted as per the culture and sensitivity results from pancreatic aspirate or necrosectomy. 
Antifungal cover with fluconazole, or echinocandins may be added if risk factors for disseminated candidiasis.
For nosocomial infections, depending on the culture and sensitivity data, colistin/ tigecycline may be used.

Cholangitis, cholecystitis

As for community  associated complicated intra-abdominal infections

Liver Abscess

Cefoperazone-sulbactam or piperacillin-tazobactam with metronidazole to cover for possible bacterial and amoebic etiology

The treatment should be changed as per culture report and amoebic serology subsequently.