•Giardia lamblia, a one-cell parasite, usually contracted by food or water poisoning, causing diarrhea, bloating, foul smelling burps
. For diagnosis and
treatment read about human intestinal parasites.
•Intestinal bacteria that are part of normal intestinal flora but can cause bloating, burping, flatulence or diarrhea when they overgrow; condition is called small intestinal bacterial overgrowth (SIBO) . SIBO may be also present in lactose intolerance or fructose malabsorption.