Extending drain pipe with an elbow - problem?

Good evening,

I have a question to which I cannot find or do not know the answer. Due to our existing kitchen and the wall connections in our house, I need to extend the drain by 1.5m. I know that the pipe requires a minimum slope of 1-2%. Unfortunately, both an outlet and the water connection are in the way of the pipe. I have tried everything with numerous different configurations.

The only possibility I have found so far:
The pipe comes out of the wall and first goes down at a 45° angle for 15-20cm and from there goes up to the sink. Now my question is: Is the bend downwards a problem? Or is that not allowed at all? I would appreciate feedback.

So wastewater would always remain in the lower part? It will not remain permanently sealed at the couplings, problems are thus pre-programmed. What you could do: install a 50mm flexible pipe/hose in the part where water remains standing, so that there are no connection points there. But even that would be an absolute emergency solution, as food residues, etc. will then accumulate there.

Yes, exactly. Too bad.. I kind of suspected that. Then it will be difficult now.. since I don't know how to create a slope :-( Well, I will keep thinking about it.

Hi

Why don’t you expose the wastewater pipe a bit further to then reach a deeper position

Olli