Hi and welcome to Healthcaremagic. Thank you for your query. I understand your concerns and I will try to help you as much as I can. Yes, this may be gallbladder issue but if only ALP is elevated then I dont think that urgent measures are required. If other liver markers are fine than it may be just small gallbladder stone that passed so only lab follow up in few weeks is required. You can do ultrasound to see if stones are present, but CT scan is not necessary. You need to change your dietary habits first. Need to avoid fried food, carbonated drinks, coffee, alcohol and spicy food. You should eat more milk products, vegetables and boiled food. SOme other causes are less common and include biliary tree pathology, but this is not likely at this point if no symptoms are present and liver markers are fine, I hope I have answered you query. If you have any further questions you can contact us in every time. Kindly regards. Wish you a good health.