No, Crohn's disease is not related to lower back pain. It is a disease of intenstines. It may affect any part of gastrointestinal tract. This disease is also known as granulomatous colitis. Symptoms of this disease are abdominal pain, diarrhea, vomiting etc. skin rashes also may present. The eye also may be inflammated.
Yes, Crohn's Disease can be related to lower back pain. Some people with Crohn's disease have inflammation of the sacroiliac joint, or inflammation in other joints in the lower back.