Gastrointestinal System

Step 1: View Clinicals

A 48 year old man presents with episodic watery diarrhea for five months, which was predominantly nocturnal. He had also lost 8 kg of weight during the preceding year.

His medical history is unremarkable, and he is not on any drugs. There is no significant history of travel.

His serum albumin is found to be 2.5 g/dL (normal: 3.5 to 5.5 g/dL).

Step 2: Order Relevant Investigations

1. Serum Electrolytes


Na+: 132 mEq/L (135 - 145)

K+: 3.4 mEq/L (3.5 - 5.5)

Cl-: 97 mEq/L (95 - 105)

2. Stool Analysis


No amoeba, ova or cysts identified

No pus cells or erythrocytes

Fecal fat analysis: 9 g/24h (normal: 2 - 6)

Bacterial and protozoal cultures: negative

3. Morning Cortisol


22 mcg/dl (<3: adrenal insufficiency; 3-19: indeterminate; 19-25: unambiguously normal)

4. Upper GI Endoscopy + Biopsy


The duodenal mucosa shows pale yellow shaggy areas alternating with erythematous regions. Biopsies reveal expanded villi containing macrophages which stain positive to the Periodic Acid-Schiff (PAS) stain.

Step 3: Select Appropriate Management

1. Antibiotics


2. Steroids


3. Surgical resection


4. Dietary restrictions