NEC is a difficult disease to learn about: it occurs mostly in premature infants, has no ‘adult’ or ‘older childhood’ equivalent disease and occurs unpredictably and suddenly. We know that research improves care and outcomes for preterm infants, and we can learn about why some babies get NEC from their stool, urine, blood and tissue (if they needed surgery). However sampling specifically for research is difficult in these tiny patients, particularly at or around the onset of