This sounds like Giardia, a common and difficult to diagnose condition, that <span style = 'background-color: #dae8f4'>causes</span>
flatulence, foul smelling burps and farts
, sometimes vomiting and intermittent crampy pain and diarrhoea. It is relatively easy to treat with a single course of Tinidazole 2g, which may need to be repeated a week later, or a week of metronidazole. It can be sometimes diagnosed by a stool sample, but is often missed, as the parasite that causes
it is only intermittently shed in faeces.