Floods are among the most common hazards in the world and can result in a devastating impact on human life and property. The impact of floods on humans can be traced directly to factors such as the location and topography of the area, as well as demographics and characteristics of the existing environment. Pakistan is currently facing the worst humanitarian crisis in history. It is faced with daunting challenges of reviving and reconstructing almost one fourth of the population. Latest government figures indicate that over 14 million people have been affected by the floods. More than 1.5 million cases of diarrheal diseases have been reported so far. Over 235,000 people have been treated at the diarrhea treatment centers set up in the aftermath of the floods. Floods are unique in their nature since every region is characterized by diverse factors. This paper examines closely the diarrheal outbreak in the flood-ravaged provinces of Pakistan. The study looks at the extent of spread of diarrhea across different time periods through a comparative analysis of different provinces affected. There are many direct factors that affect the severity and scale of floods and, in turn, impact human health like contaminated water, cramped living conditions and lack of sanitation facilities. The paper explores the pre-existing indirect factors responsible for the spread of outbreak in the provinces. These range from geography, socio-economic conditions, demographic features, topography, and community infrastructure. These factors play an extremely pivotal role in determining the nature of response required to control the diarrheal outbreak.