25-year-old male patient with three-week history of diarrhea

Initial History: Essential Facts:
• Three week history of mucoid, non-bloody diarrhea
• Has prolonged diarrhea (three weeks)
• There is associated abdominal cramps

Comments
Diarrhea wakes patient up, meaning it is a non-functional diarrhea; functional diarrhea will not wake patient up. It is of recent onset, so irritable bowel syndrome is unlikely. Diarrhea is mucoid, so there is an infectious etiology; it is non-bloody, so there is no invasiveness of the GI tract.

Differentials at this time include:
• Infectious diarrhea (e.g. Giardiasis)
• Dysentery
• Inflammatory bowel disease

Giardiasis is one of the commonest causes of diarrhea in the adult population
Let us go on to perform the physical examination. We are interested in the following systems
Physical Examination:
• General appearance
• Abdomen/rectum
• Extremities
• Cardiovascular system
• Skin
• Lungs

Confirm your choice of PE. Afterwards, click on the Order button to place the following orders.

• Electrolytes
• BUN/ Creatinine
• CBC statim
• Stool for ova and parasites, C/S, clostridium
• Serum amylase and lipase to rule out Pancreatitis. Amylase is sensitive but not specific; lipase is specific but not sensitive
• Abdominal X-ray to rule out toxic megacolon/perforation, acute series

Comments
We have done everything we can do at this stage. Let us advance the clock to see the next available result. What we do next will be determined by what we get from the lab results. Advance the clock until you get the results:

Ova and parasite: positive for Giardia lamblia

Now that our diagnosis is confirmed, it is time to treat the patient. Click the Order button below the screen and order

Flagyl oral, continuous
We can now schedule an appointment for the patient. Let us see him in 1 week for follow-up.

Diagnosis: Giardiasis
End of case