Diarrhoea is a common problem in both livestock and humans, especially in children in Kenya. Among the people of Mathare North, water is generally not adequate and many cases of food and/or waterborne diarrhoeal diseases have been reported, including amoebiases and gastro-enteritis. This book reports on the isolation and identification of various etiological agents of diarrhoea as well as the bacterial antibiotic resistance patterns in Mathare north, Nairobi District. One hundred and seventy two faecal samples from patients presenting with diarrhoea at Upendo health centre were collected. Examinations of wet preparations were done using direct microscopy to detect parasites. Samples were then transported to the Walter Reed Institute-KEMRI for bacteriological, biochemical, serological and drug sensitivity testing by disc diffusion method. Molecular characterization of Campylobacter spp. and Escherichia coli spp. were performed using Polymerase Chain Reaction (PCR). This book will be useful for research, health, laboratory and university students looking for information on diarrhoeal causing pathogens as well as bacterial antibiotic resistance patterns in a resource limited setting.