The French-Algerian gesticulated at Dunfermline fans as he left the pitch following the 1-1 draw at East End Park on Saturday.
It is not the first time the centre-half has allowed himself to become embroiled in off-the-ball incidents in the 2013/14 campaign.
He was sent off after the game against Airdrie at the Excelsior Stadium in January after becoming involved in an altercation with opposing players.
And the defender was red-carded for kicking an opposing player in an SPFL League One match against Brechin City at Ibrox in February.
McCoist, who has already spoken to the former Southend United and Ipswich Town player about his behaviour this term, admitted it is time to do so again.
He said: "I asked Kenny (McDowell) if he thought that I could change him at the end of the game and he just looked at me as if I was half-daft.
"Bilel is what he is. He is one of these guys who attracts attention from all supports. I would far rather that he concentrated on his game 100 per cent.
"Obviously, there are times when he lets people and occasions get to him. If he was more focused then I think it would help Bilel and the team.
"As long as he doesn't get in any trouble, that is the most important thing. But we will have the chat with him again and see what happens."