yes colon problems can aggrevate sciatica but not produce them in the first place.
check my website for info about back pains and read about it in the forum: dorn method forum.
There is always a physical root cause in the structural system when we have any kind of back pain that is a misalignment in the sacrum.
Many people have all kinds of conditions but no back pain, and many have back pain but no other severe conditions right? If different conditions cause back pain other than on the structural level than everyone with these conditions should have back pain and vise versa.
We need to re-align the spine in order to heal the condition and of course all other therapies that may contribute to the condition should be tried.
A combination is most likely best.
Non Physical Imbalances are very important in this scenario as well.