I am sorry that your question was unanswered for quite long.
Do you have numbness or tingling in the lower limb?
Are you overweight?
What are the specialists you have consulted?
My weight 70kgs
I have consulted Orthopedic doctor
Following measures would be helpful for your back pain and L5-S1 changes;
1) Back care in the activities of daily living, which is an integral component of the treatment of back problems. Back education is one of the most important thing which teaches the basic body mechanics, like correct posture for standing, standing at a desk or drawing board, sitting, brushing teeth, washing the face, pushing and pulling a weight, lifting a weight, getting in and out of bed, sleeping, getting into and sitting in a car. The training for these routine activity helps in preventing the spasm of the muscles. One needs to consult an occupational therapist or physical therapist which can educate about the proper and improper behaviors when back is painful in case they have to sit, bend forward, lie down, walk, cough, or sneeze. Following more need to be done:
a) Avoid activities which increases the pain.
b) Rest intermittently
c) Avoid bending at 90 degrees
d) Pushing and pulling should be avoided till pain subsides
f) Avoid prolonged sitting and standing
g) Avoid sitting or sleeping on floor
2) Anti-inflammatory analgesics like ibuprofen, other analgesics and muscle relaxants
3) Local analgesic gels or sprays / ointment
4) Hot fomentation
5) Electrotherapy like trans cutaneous electrical nerve stimulation: done by physical therapist. Other thing are ice packs, heating pads, electrical stimulation, phonophoresis, iontophoresis, relaxation, and biofeedback.
6) Good supervised physiotherapy: The exercises consist of abdominal bracing, modified sit-ups, double-knee-to-chest or low back stretches, seat lifts, mountain and sag exercises, knee-to-elbow exercises, hamstring stretches, extension exercises, and extension flexibility exercises. Swimming exercises (pool exercises) are best for back pain. Initial stretching and later strengthening exercises are taught.
7) Lumbosacral corset or support or brace
8) Epidural steroid shots
9) Surgery is usually last resort, when the above conservative measures fail. You can start the following exercises;
1) Straight leg raising: Lie on the bed with your back and remain in a relaxed position. Slowly raise one of your legs upward and keep it as straight as possible. Count up to ten, and slowly bring down the leg. Do the same with the other leg. Repeat this exercise ten times.
2) Curl ups; lie on the back with knees bent, fold arms across the chest, tilt the pelvis to flatten the back, and curl-up lifting the head and shoulders from the bed / couch. Hold for ten seconds, then slowly lower to starting position. As strength builds, aim to complete one sets of ten curls. The exercise should be done twice a day (both the sets).
This is a slide show for the exercises (you can pick up your own set, which suits you);
Please feel free for your follow up questions.
After doing all the exercise suggested by you, will my problem will solved permanently ? i mean back pain and gap between L5/S1. and how long i should continue these exercise, you have also mentioned about some medicine ibuprofen etc. what is frequency for taking these medicines.
Ibuprofen can be taken three to four times a day. Usually exercises will make you pain free in three weeks. Some mild physical fitness exercises and back care in the activities of the daily living usually need to be observed so any backache recurrence can be prevented.
It is pleasure and privilege assisting you.
I hope this was helpful to you. If it was, please remember to ACCEPT the answer so I can get compensated for my work. If you have any more questions, please feel free to ask. I am truly privileged to help you, and I want to make sure that you are satisfied with the answer. Good luck!