I have constipation problem. I checked with gastroenterologist. He recommended some test like hemoglobin , vitamin d, cbc test, urin test, blood sugar test, calcium test,etc. In this all test found hemoglobin level is low(11.2), and found vitamin D defficiency(8.6) and other was normal. I have also some problems like weak and brittle hair, i have spex also, acne problem, weakness in body, tingling and numbness in hands and feet, i eat lots of vegans and salads daily but zero effects on body. The main problem is constipation daily i have slow stool problem. I want to know is this is the problem of celiac disease. What is the blood test available for celiac disease.