I need to move the toilet drain on my lower level. The drain was roughed in when the house was built and of coarse both shower and toilet drains are in the wrong place. I broke up the concrete floor and moved the shower drain with no problem but I'm concerned about the toilet drain if I move it where it needs to be, presently I would need to place a 90 degree elbow in the pipe as it runs horizontal. Would the toilet drain properly or would it clog with the 90 degree bend in the pipe?

As long as you still have fall on the pipe a 90 should not cause a problem. However, if you could use a 45 instad of a 90 that would be better.

The 45 is not a option. How much pitch do I need? The length of pipe would only be 18 inches to the 90.

You can use one regular 45 and one Street 45 to make the turn. This way you will save about 2".
Question: can you snap a good photo of your situation and post it for us to see ? Thanks !

Milo

Would a 45 and a street 45 put together to make a 90 or a long sweep 90 work for you? 1/8" of pitch for 18" would be enough.

Hey Robert, can't address pitch until you tell us the diameter of your pipe. Smaller than 4" needa 1/4" per foot. 4" and larger can do fine with half that pitch.