**Question:** A 10-year-old child presents with recurrent episodes of blood in stool. On examination, his lips show the following. He may be suffering from?

A. Coeliac disease
B. Iron deficiency anaemia
C. Leishmaniasis
D. Diverticulitis

**Core Concept:** Blood in stool (melena) in children can be due to various causes, including nutritional deficiencies, infections, and autoimmune disorders. The clinical presentation often includes pallor, fatigue, and growth retardation.

**Why the Correct Answer is Right:**

B. Iron deficiency anaemia (IDA) is a common cause of blood in stool in children. It results from the deficiency of iron, a crucial component of hemoglobin. Iron deficiency leads to decreased red blood cell production, causing pallor, fatigue, and impaired growth. The presence of blood in stool and pale mucous membranes (as seen on examination) further supports the diagnosis.

**Why Each Wrong Option is Incorrect:**

A. Coeliac disease is an autoimmune disorder characterized by malabsorption of nutrients, including iron. While blood in stool (melena) can be a presenting symptom, the child would also exhibit other symptoms such as abdominal pain, diarrhoea, weight loss, and failure to thrive.

C. Leishmaniasis is an infectious disease caused by protozoan parasites of the Leishmania genus. It is typically associated with splenomegaly, hepatomegaly, and lymphadenopathy, rather than blood in stool.

D. Diverticulitis is an inflammation of the diverticula in the colon. Blood in stool is not a typical presenting symptom in diverticulitis, whereas it is more commonly associated with abdominal pain, fever, and rectal bleeding.

**Clinical Pearl:** Examination of the lips in children with blood in stool can provide valuable information for the clinician. The presence of pallor and/or petechiae on mucous membranes indicates iron deficiency anaemia as a possible cause. However, it is essential to perform further diagnostic tests to confirm the diagnosis and rule out other potential causes like malabsorption disorders and infections.