**Question:** The earliest manifestation seen after Gastrectomy

A. Hyperphagia
B. Gastric emptying
C. Anorexia
D. Nausea and vomiting

**Correct Answer:** **D. Nausea and vomiting**

**Core Concept:**
After a gastrectomy, the immediate postoperative period is characterized by a series of physiological changes that may lead to the observed symptoms. Gastrectomy is the surgical removal of part or all of the stomach. The primary function of the stomach is the mechanical and chemical breakdown of food, as well as the release of gastric juice that aids in digestion.

**Why the Correct Answer is Right:**
Nausea and vomiting are typically the first symptoms experienced after gastrectomy. They arise due to the absence of the stomach, which is responsible for the production of gastric juice containing hydrochloric acid, pepsin, and intrinsic factor. The loss of these substances leads to:

1. **Gastric acid deficiency:** The absence of hydrochloric acid in the stomach reduces the pH of gastric secretions, which is essential for the activation of pepsin and the absorption of intrinsic factor.
2. **Lack of intrinsic factor:** Intrinsic factor is necessary for the absorption of vitamin B12 in the terminal ileum. Deficiency of intrinsic factor can lead to pernicious anemia.
3. **Impaired digestion:** The absence of gastric juice hinders the mechanical breakdown of food, leading to the inability to fully digest proteins, carbohydrates, and fats.

**Why Each Wrong Option is Incorrect:**

A. **Hyperphagia (increased appetite):** Hyperphagia occurs due to the neuroendocrine changes post-surgery, including the release of gastrointestinal peptides like cholecystokinin (CCK), gastrin, and motilin. These hormones increase the perception of hunger and decrease the feeling of fullness, leading to increased food intake.

B. **Gastric emptying:** Gastric emptying is not directly affected by gastrectomy, as it is regulated by various factors such as vagal innervation, hormonal regulation, and mechanical factors. Post-surgical changes in these factors might lead to delayed gastric emptying, but this is not the primary cause of the early symptoms after gastrectomy.

C. **Anorexia (reduced appetite):** Anorexia is a normal response to surgery and trauma, which often leads to decreased food intake. However, anorexia is not the first symptom after gastrectomy.

During the recovery period, the patient's body tries to conserve energy and protect against further injury by reducing food intake, which results in anorexia. In contrast, after gastrectomy, the patient experiences increased hunger due to the release of gastrointestinal peptides like CCK, gastrin, and motilin, which stimulate appetite.

D. **Vitamin B12 deficiency (pernicious anemia):** While vitamin B12 deficiency can occur after gastrectomy due to the lack of intrinsic factor production, it is not the first symptom experienced after surgery. The primary symptom following gast