**Core Concept**
Omphalocoele and gastroschisis are two distinct congenital anomalies of the abdominal wall, both presenting as protrusions in the neonatal period. The key to distinguishing between these conditions lies in their embryological origin, anatomical characteristics, and associated gastrointestinal anomalies.

**Why the Correct Answer is Right**
Omphalocoele is a midline defect in the abdominal wall, resulting from a failure of the cloacal membrane to close during embryogenesis. This condition is often associated with intestinal malrotation, which occurs due to the abnormal development of the midgut loop. The malrotation can lead to volvulus, obstruction, or even intestinal ischemia. In contrast, gastroschisis is a lateral defect in the abdominal wall, typically occurring to the right of the umbilicus, and is not associated with intestinal malrotation.

**Why Each Wrong Option is Incorrect**
**Option A:** This statement is incorrect because omphalocoele is typically covered by a sac, which contains the herniated bowel, amniotic fluid, and sometimes even the liver or other organs. Gastroschisis, on the other hand, is characterized by the absence of a sac.
**Option C:** This statement is incorrect because omphalocoele can sometimes be associated with a normal or even hypertrophied abdominal musculature. The presence or absence of abdominal musculature is not a reliable distinguishing feature between omphalocoele and gastroschisis.
**Option D:** This statement is incorrect because the umbilicus is usually attached to the abdominal wall musculature in both omphalocoele and gastroschisis. The location and attachment of the umbilicus are not reliable distinguishing features between these conditions.

**Clinical Pearl / High-Yield Fact**
A key difference between omphalocoele and gastroschisis is the presence of intestinal malrotation in omphalocoele, which increases the risk of complications such as volvulus and intestinal obstruction. This distinction is crucial for determining the appropriate surgical approach and postoperative management for these neonates.

**✓ Correct Answer: B. Associated with some or complete malrotation of bowel**