It needs to be investigated. Kindly visit a ortho doctor.

Possible. It can be confirmed on x-ray and MRI

Excessive hair growth on the lower back of a 7-year-old child can be a sign of a spinal abnormality, such as spina bifida. Spina bifida is a congenital condition where the spinal column fails to close properly during fetal development, leaving the spinal cord exposed or protruding through the skin. The hair growth may occur because of abnormal nerve impulses in the area of the spine affected by the spina bifida. However, it is important to note that not all cases of excessive hair growth on the lower back are related to spina bifida. There can be other causes of this symptom, such as hormonal imbalances or genetics. In addition to stomach pain, other symptoms of spinal deformity may include back pain, weakness or numbness in the legs, difficulty walking or standing, and bowel or bladder dysfunction. If your son's pediatrician suspects a spinal abnormality, further tests such as an MRI or X-ray may be recommended to confirm the diagnosis. Treatment for spinal deformity depends on the severity and type of the condition. Mild cases may require no treatment, while more severe cases may require surgery. It is important to follow your son's pediatrician's recommendations and to seek the advice of a pediatric specialist if necessary. Early detection and treatment of spinal abnormalities can help prevent complications and improve outcomes.

Hello..can you send the clinical picture..pls confirm by physical examination and  by getting an MRI scan and x-ray..

Chances are there..can u send the pic...or u can visit a neurosurgeon.

Can be.. but not always.. just confirm by visiting orthopedic or neurosurgeon 

Yes possible but confirmation must as per your treating doctor advice Consult me search browse on goggle practo website Dr Rajinder sharma senior Orthopaedic neurospine joint Replace surgeon ,42 years expertise chandigarh health Department Govt Multispeciality Hospital retired Chandigarh(U.T)