Have extreme gas and sometimes bloating. this happened after i had a virus a couple weeks ago. what can it be, it's been going on for weeks?

Post-Infectious IBS: If it is several Weeks since the viral gastroenteritis and you still have symptoms . You need to have your stool checked on 3 separate days to rule out a secondary bacterial or parasitic infection like Giardia. Also blood work and an abdominal ultrasound would be appropriate at this stage. I would also recommend a gluten free diet ,high in fiber and a good probiotic. I like the Gutbliss diet.

Villous atrophy: sometines following a viral infection ( viral gastroenteritis) the villi that line the inner side of the bowel become flat ( partial Villius atrophy ) and that can lead to carbohydrate malabsorption, which in turn leads to excess gas production. Avoid regular milk ( lactose malabsorption) and juices for a couple of weeks until the villi recover