This study aimed to investigate the relationship between gastrointestinal tract infection and dengue hemorrhagic fever. Dengue hemorrhagic fever is a syndrome caused by the dengue virus and primarily affects children below ten years of age and is spread by the Aedes aegypti mosquito. Gastrointestinal tract infection is a bacterial and parasitic infection that leads to gastrointestinal tract inflammation which involves the small intestine and the stomach. The relationship between the two can be manifested by gastrointestinal bleeding, acute pancreatitis, and fulminant liver failure. In this research work, 600 blood and feces samples of different ages and sex (7-8 worms) were collected from Jeddah city. From the blood samples, serum was made and stored at -20°C until use. The frozen sera samples were investigated for sero-detection of DENV-NS1 antigen as a rapid, sensitive, and cost-effective test to detect asymptomatic acute DENV-infected donors and anti-DENV IgM and IgG antibodies. Feces samples were processed for the detection of parasites. The data acquired from these samples of all the 600 participants were analyzed and interpreted, followed by statistical analysis using GraphPad Prism 5.0 software. All the values were considered significant, which showed a value of less than 0.05. Results were expressed as with the range. This article documents that gastrointestinal tract manifestations frequently occur among patients with dengue hemorrhagic fever. There are close relationships between gastrointestinal tract infection and dengue hemorrhagic fever. In current work, it was established that dengue fever leads to gastrointestinal tract bleeding in the presence of intestinal parasites. Therefore, failure to identify the patients with this infection early enough can lead to an increased morbidity and mortality rate.