What causes severe flatulance could it be connected to constipation which i have been suffering with for the past two weeks?

Yes: Flatulence is gas that is created by the bacteria that colonize your gut, making up to 75% of your stool volume. Constipation is retention of stool, meaning more bacteria=more gas. A high fiber diet improves constipation, easing passage of stool, less bacteria, less flatulence-short term use of laxatives may help too, along with diet and exercise, as always!