This research analyzed the prevalence of water sanitation at the household level against gastrointestinal disease occurrence in the urban slum setting of South Okkalapa Township, Myanmar, using cross-sectional study design techniques. A total of 364 household respondents were interviewed face to face by well-trained research assistants using structured questionnaires. Chi-square tests and multiple logistic regression analyses were used to determine the association between independent and dependent variables. Results showed that the source of household water (OR: 13.58, 95% CI: 6.90-26.74), and the types of drinking water (OR: 1.85, 95% CI: 0.92-3.71), were significantly associated with gastrointestinal diseases (p-value<0.05). After adjustment for confounding factors, this study found that occupation (AOR: 2.63, 95% CI: 1.25-5.54), employment status (AOR: 2.25, 95% CI: 1.01-5.01), type of household toilet (AOR: 8.66, 95% CI: 4.03-18.60), sources of household water (AOR: 6.56, 95% CI: 2.86-15.08), and the method of vector control (AOR: 3.12, 95% CI: 1.37-7.30) were all significantly associated with gastrointestinal diseases (p-value<0.05). Health education and appropriate technology for household water, sanitary latrines, environmental sanitation and waste disposal, and the implementation of policies focusing on systematic water management are therefore urgently required to control the spread of waterborne diseases.