My doctor told me i have sciatica but i have no back pain just buttock and leg pain which is more intense at night and early morning why is that?

See below: Many people with sciatica experience just buttock and leg pain without back pain. Sciatica will often calm down on its own however if it does not after a few weeks or if you experience symptoms of weakness in the leg, or any problems moving your bowels or urinating you should see your doctor right away.

For most people the : Leg pain with or without buttock pain is the main symptom. There is usually no or minimal back pain although it may start with back pain and then as the leg pain starts or worsens , the back pain decreases or resolves. The pain is due to direct nerve compression. The timing of your pain, however, is not typical as most feel better at rest . You need a MRI ideally or ct to determine the cause.

Yes It Can: This pain in the distribution as you suggested is the result of an irritated nerve or facet joints or other injury typically in the lumbar spine (low back) which are caused by herniated disks, spinal stenosis or degenerative disc disease, etc requiring further evaluation by a spine specialist and may be candidate for facet injections/radiofrequency ablation and epidural steroid injection.