Waste smell and gurgle after changing from septic tank to mains drains

[trickyfox]

We've recently gone from a septic tank to mains drainage. Since this happened we are getting a slight sewerage smell in the bathroom and the shower waste 'gurgles' (for want of a better word). The waste connection goes straight to the mains so there is now a long uninterrupted run and I'm guessing to 'gurgle' is the water rushing down the pipe. I'm also guessing this rushing is breaking the 'seal' on the trap.
Is there any way that this can be remedied easily? If we installed an inspection chamber directly outside the bathroom, would this (breaking the run as it were) solve the problem? Any suggestions appreciated.

[stoneyboy]

Hi trickyfox.
The easiest thing to try first is to fit an air admittance valve in the pipe work.
Regards S

[trickyfox]

Thanks Stonyboy. I'm not sure this would work though. There is a 'rodding point' in the drain run and we've left this 'uncovered' but this didn't help.