 Stool testing Clostridium difficile by polymerase chain reaction PCR PCR for Shigella, Salmonella, E.coli verotoxin, Campylobacter Cryptosporidium Ova and parasites Serological testing HIV, type 1 and 2 Hepatitis A IgM Hepatitis B surface antigen, hepatitis B core antibody and hepatitis B surface antibody. 