**Question:** All are seen in lactose intolerance EXCEPT:-

A. abdominal pain
B. bloating
C. diarrhoea
D. constipation

**Core Concept:** Lactose intolerance is a condition where an individual's body is unable to break down lactose, a sugar found in milk and dairy products, due to a deficiency of lactase enzyme. The deficiency results in symptoms like abdominal pain, bloating, diarrhoea, and flatulence.

**Why the Correct Answer is Right:**

Option D (constipation) is not a typical symptom of lactose intolerance. Unlike lactose intolerance, constipation is a condition characterized by infrequent bowel movements, hard stools, and difficulty in defecation. Constipation is often caused by dietary factors, hormonal imbalances, or a lack of fiber in the diet, whereas lactose intolerance symptoms are predominantly related to lactose malabsorption and subsequent gastrointestinal distress.

**Why Each Wrong Option is Incorrect:**

Option A (abdominal pain) is a common symptom associated with lactose intolerance. The lactose in lactose intolerance stimulates the release of gastric acid and enzymes in the small intestine. This process can lead to abdominal pain, which is a result of the increased bacterial fermentation of lactose.

Option B (bloating) is also a common symptom of lactose intolerance. The increased bacterial fermentation of lactose in the large intestine results in gas production, which causes bloating and distension in affected individuals.

Option C (diarrhoea) is another common symptom of lactose intolerance. The increased bacterial fermentation of lactose leads to the production of large volumes of water-rich feces, resulting in diarrhoea.

**Clinical Pearl:**

Diagnosing lactose intolerance can be challenging as symptoms can overlap with other gastrointestinal disorders. A diagnostic trial with lactose-free diet for a few days can help confirm lactose intolerance. If symptoms improve, lactose-free diet can be reintroduced to determine the lactose load causing the symptoms. Consulting a healthcare professional is essential for accurate diagnosis and management of lactose intolerance.