Check your Alertness Level. I don't have the whole interview process in my head and if you loose any Alertness in the interview itself, but if get to the poop ending that means that your Alertness at that point is 0 which leads to the bad end.
You can check your Alertness level when you check Alona's status (ESC-Key > Status Menu > Alona) and it's the value on the bottom of the status screen below INT:
View attachment 1397162
So the best way is to have this Value above 0 when you go to the interview. If I remember right you gain a bit Alertness for every Drug Evidence you found at the end of the School Story.
If you can't find a way to increase your Alertness you can either find some cheat editor to change Alona's Alertness value or if you can't do that either, I've created a little patch:
Google Drive
It changes the interview room a bit. So before Alona is about to go through the last part of the interview, a decision is added for Alona to either focus or to let go. If she focuses she gains 2 alertness which should allow her to avoid the poop end, if she lets go everything continues. This decision comes anyway no matter if you have enough alertness or not.
to use this patch go to: Game Folder > Data
rename Map081.rxdata to something like Map081.backup
then copy the Map081.rxdata from the archive you downloaded to the Data folder.
If you start the game now you should get this little cheat that helps you over the poop ending.