Lil Wayne: It Wasn't Sizzurp ... I Just Didn't Take My Meds

Lil Wayne says his latest round of seizures were not triggered by sizzurp ... he says it all emanates from a chronic condition -- epilepsy, and the medications he takes to control it.

The rapper's private jet was forced to make 2 emergency landings earlier this week because he hadn't been taking his meds and had several epileptic attacks on the plane.

As for why he wasn't taking his Rx ... Wayne's rep tells us he went to a pharmacy in Milwaukee where he was performing but they didn't have the medicine in stock. He thought he could do without it for a few days, but he was wrong.

TMZ broke the story ... people who were at the club tell us Wayne was drinking "massive amounts" of sizzurp before the seizures started.

As we previously reported, Lil Wayne returned to the stage just 2 days after he was released from the hospital.