I have been in touch with sgt Matt Crowley from the community police team for Stirchley and he has visited the site and I have copied his reply to me.
(Thank you for your email. Please feel free to repost anything from this email on the Stirchley website.
Right. That was disgusting. I have been down to the area described below and there are a number of points in that location and more broadly down the grassed area by the river where there is human faeces and associated tissues and newspaper. I can’t tell how you how lowly I regard people who would act in this way in an area where our kids play and make dens. It is not acceptable.)
I have also been copied into the emails that Matt sent to various council departments and local councillors, and the area is to be cleaned up with a couple of days (might have even been done by now)and I would imagine that steps are being taken to catch the culprits.
Let me know when you see the improvement.
Pete, Stirchley neighbourhood forum