Background and study aim: Giardiasis is a gastrointestinal disease,
caused by the protozoan parasites Giardia lamblia. Thisinfection occurs through ingestion of contaminated water or food by  Giardia lamblia cysts. The aim of this study was to correlate between the presence of Giardia lambilia and different gastrointestinal symptoms.
Subjects and methods: experimental study was performed at the laboratories of Parasitology Department, Faculty of Medicine, Sohag University from October 2016 to October 2017. It was done on 93 patients, who had Giardia from different localities in Sohag governorate after examination by saline and iodine wet mount. History taking and questionnaire survey about gastrointestinal symptoms was followed.
Results: Diarrhea was the first complaint that affected all cases, abdominal colic was the second most common complaint affecting 84 (90.3 %) cases, followed by failure to thrive affecting 32 (34.5 %) cases, followed by abdominal distension affecting 26 (28 %) cases, and vomiting affecting 6 (6.6 %) of cases.
Conclusion: We concluded that However diarrhea was the first complaint that affected all cases, abdominal colic was the second most common complaint affecting 84 (90.3 %) cases, followed by failure to thrive affecting 32 (34.5 %) cases, followed by abdominal distension affecting 26 (28 %) cases, and vomiting affecting 6 (6.6 %) of cases.