What could be causing these small lymph nodes in ileocolic mesentery?

Mesenteric adenitis: Mesenteric adenitis (enlargement of lymph nodes in abdominal mesentery) is commonly seen in conditions that mimic acute appendicitis. When accompanied by inflammation of the ileum, & crohn's disease has been excluded, consider bacterial infection caused by yersinia enterocolitica, campylobacter, salmonella. Adenitis may also reflect non-gi inflammatory processes in the abdomen.