A 42-year-old man presents with a 6-month history of persistent diarrhea, weight loss, and generalized weakness. He reports that his symptoms began after traveling to a tropical region for a work assignment. Initially, he experienced intermittent episodes of diarrhea, but over time, the frequency increased to several times a day, accompanied by abdominal cramps and bloating. He also notes fatigue and difficulty concentrating. On examination, he appears pale and malnourished. Laboratory tests reveal macrocytic anemia, low serum folate, and vitamin B12 deficiency. Stool tests are negative for infectious causes, and a small bowel biopsy shows villous atrophy, suggestive of tropical sprue. The patient is started on antibiotics and nutritional supplementation, including folic acid and vitamin B12. He experiences gradual improvement in symptoms over the following weeks.