Resuming on 2-1, Warwicks added thirteen runs before Darren Maddy was out for three.
Varun Chopra made 27 before Murali Kartik came to the fore. Firstly he caught Rikki Clarke who had made 17 before taking the first of five wickets when Jim Troughton went for 27.
No Warwickshire batsman bettered 27 runs and against the slow left arm of Kartik, the batsman suffered and Warwicks were all out for an embarrassing 140 which left them 128 behind Somerset's first innings score.
When the visitors batted for a second time, Chris Woakes removed danger man Marcus Trescothwick for four and had Butter LBW for 19.
Andrew Miller grabbed a wicket and this was followed by Imrain Tahir taking four wickets including those of Jack Hildreth and Craig Kieswetter as Somerset ended the day on 151-8, 279 runs ahead.
In the Test match, Ian Bell went on to complete his century. The Coventry born batsman made 128 before he was bowled by Shakib Al Hasan. Matt Prior made 93 as England were all out for 419.
Bangladesh had Tamim Iqbal make 108 but Graeme Swann took five wickets to remove Bangladesh for 216.