What Causes Recurrent Fever In A Toddler?

My 3 n hlf year old niece was admitted fr 8 days due to repeated fever on testing the crp level was 34 which should be 6 normally for kids she was released after 8 days in a fine condition after the release Her appetite had become low she would drink 150 ml of milk twice a day and as far as meals are concerned she would have just few spoons of food every meal. But in past 5 days she was not eating anything and she had severe loose motions, water has totally drained n she is so week that she cannot stand fr 2 mins she just wants to sleep . We have admitted her again 3 days back her jaundice test is negative. We also did an abdomen ct scan for which the reports are totally normal all her organs appear normal only minimal interbowel free fluid is noted, few subcentimeter sized homogenous enhancing Mecentric nodes are noted, appear non -specific ,large bowel loops are distended and are fluid filled. All bowel loops are normal in wall thickness.she is on iv 4 bottles have been consumed along wth medicines to stop loose motions but whenever we give her any solid food to eat wch she eats just 3 to 4 morsels everything comes out in motions. We are worried wat to do her motions are not stopping, 5 to 6 times a day is the frequency Need an opinion if the line of treatment done is fine Are we missing any test or diagnosis plz suggest