Connection or, perhaps a better word to use, correlation, does not necessarily imply causation. A good example is, there is a strong correlation between obesity and the development of diabetes. Obesity may not be the cause of diabetes though. However, they are inter-related or correlated. Obesity is often a strong factor in the development of diabetes. I think what Relio was saying was there may be a correlation or connection or some type of relationship between sugar and Giardia/contracting Giardasis.
It certainly seems to me that Medical Science says that a correlation exists between fungal infections of the gastrointestinal and urinary tracts and a diet high in sugar. Women should be aware of this if they have ever experienced vaginal yeast infections. Please, let's be adults.