I just started using prep h today for the irritation in my rectum for itching and burning. as soon as i put the prep h in the area it started burning do that mean it's working?

Prep H can cause stinging. It doesn't indicate healing because of the burning sensation. Perhaps you have a anal fissure & different treatment. A proctologist would be best to see for accurate diagnosis, appropriate treatment & follow-up. In the meantime ,I recommend applying warm moist compresses, pat dry and if itching is the predominant symptom, applying some cortisone cream per the pharmacist