Suggest Treatment For Constipation While Having Bulging Disc In Lumbar Spine

My son (22) has a bulging disc in his lumbar spine. Few symptoms - pain, loss of reflex in right foot. Has been doing PT successfully - less pain. Now has been constipated for the past 4 days. Should he wait to see if this passes or get an opinion from a neurosurgeon who already suggested surgery instead of PT?