Recurrent pain in abdomen with poor weight gain in a two year old

Hello learned friends, I have a two and half year old patient who has recurrent abdominal pain for the last six months. she has not put on weight for the last 8-10 mnths. Otherwise she is active and eating well, very fond of eating fish. Her sonography abdomen shows multiple enlarged mesentric lymph nodes in right iliac fossa size 23 mm by 15 mm.basic investigations of blood are normal, MT TEST is negative. Repeat sonography after 6 wks shows no change in size and no of lymph nodes, rather few showing central necrosis. ESR was 7.

Have given adequate dose and duration of appropriate antibiotic too. Should I go for CT abdomen in view of central necrosis keeping abdominal TB in mind. A gastroenterologist friend has sugessted S anti TTG levels to rule out gluten senstivity. Any sugessestions?