Necrotising enterocolitis (NEC) is a devastating disease which causes severe bowel inflammation resulting in babies becoming critically unwell. It mainly affects premature babies (who can be born as early as 22 weeks) in the first few weeks of life. A quarter of babies don't respond to intensive care treatment and require surgery to remove bowel which has died to prevent them from getting sicker. Sadly, about a third of the most unwell babies don't survive and those that do have a high incidence of significant long-term health problems. Deciding which babies will benefit from surgery is challenging and there are no objective methods used to do this currently. Surgeons must weigh up the risks and benefits of performing major surgery on a tiny baby in the knowledge that surgery itself may cause harm. This uncertainty causes delays in performing surgery. Those that have a delay are more likely to have a poor outcome. In order to improve these unfavourable outcomes it is essential to understand and define current practice in detail (i.e. indications and timing for surgery) and understand how this may be associated with outcome. These outcomes are both short term, including mortality and ability to tolerate enteral nutrition, and long term which include neurodevelopmental outcomes at 2 years of life. To do this the investigators will undertake a multicentre mixed methods study with qualitative interview of consultant paediatric surgeons shortly after making a decision to operate, or not, on a baby with NEC. The investigators will then take consent from the parents/guardian of the infant to follow-up their clinical outcomes using data linkage to routinely collected data, within the national neonatal research database. Outcomes of interest include survival, feeding outcomes, further surgical procedures and neurodevelopment at 2 years.