This study is being conducted to evaluate the safety, efficacy and pharmacokinetics/pharmacodynamics of GSK2251052 in subjects with complicated intra abdominal infections. GSK2251052 will be compared to meropenem, an IV therapy that is approved for use in the treatment of subjects with cIAI. GSK2251052 has a spectrum of microbiological activity that includes pathogens responsible for cIAI.