Hi, Thanks for writing in to us. Swollen abdominal lymphnodes (mesentric lymphadenopathy) can cause significant pain to a child. It can also cause changes in bowel habits like diarrhoea. This happens when there is infection of the bowel like typhoid enteric fever. the enlargement of mesenteric lymph nodes frequently causes abdominal pain in children, being an indication for laboratory investigations. Vomiting and fever are the most common other symptoms in these patients. Ultrasonographic examination usually shows large enlargement of lymph nodes, sometimes in conglomerates, with tendency to invagination. Acute diarrhea and respiratory tract infection are the most frequent reasons of the enlargement of abdominal lymph nodes. In about 20% of the children primary mesenteric lymphadenopathy is diagnosed. A complete course of antibiotics (flagyl) are essential to cure the problem. Food and water hygiene should also be maintained. Hope this helps