Hi. My son is three. He has hypotonia- falls a lot- and has severe constipation. He also has a dimple in his butt crack. The doctor thought he had a tethered cord, and did an MRI. The MRI showed no evidence of tethered cord, but indicated that his spinal cord came down longer than it should and is low lying. We see a neurologist next month. Can a tethered cord be overlooked on an MRI? And, can a neurologist even help us? OR, should we be seeing a neurosurgeon. We don't know what to do next. The doctor thinks that perhaps the low lying cord is causing the hypotnoia and the constipation. Any advice is appreciated. Thanks!