Malrotation presents as -a) Mass abdomenb) Bleeding PRc) Billious vomitingd) Haematemesis

**Core Concept**
Malrotation of the gut is a congenital anomaly where the midgut fails to return to its normal anatomical position during fetal development. This leads to an abnormal relationship between the small intestine and the other abdominal structures, including the superior mesenteric artery and the duodenum.

**Why the Correct Answer is Right**
The most common presentation of malrotation is bilious vomiting, which occurs due to the obstruction of the intestinal lumen by the malrotated intestine. This is often seen in infants and young children. The malrotation can lead to volvulus, a twisting of the intestine around the superior mesenteric artery, which can cause ischemia and infarction of the intestine. The bilious nature of the vomiting is a key clinical clue to the diagnosis, as it suggests that the obstruction is located beyond the pylorus.

**Why Each Wrong Option is Incorrect**
* **Option A:** Mass abdomen - While a palpable abdominal mass may be present in some cases of malrotation, it is not the most common presentation.
* **Option B:** Bleeding PR - Gastrointestinal bleeding is not a typical presentation of malrotation.
* **Option D:** Haematemesis - Vomiting blood is not a characteristic feature of malrotation.

**Clinical Pearl / High-Yield Fact**
In infants and young children with bilious vomiting, the diagnosis of malrotation should be considered and investigated promptly, as delay in diagnosis can lead to complications such as intestinal ischemia and infarction.

**Correct Answer:** C. Billious vomiting