A 22-year-old woman presents to the clinic for evaluation of fatigue. She has not felt well for the past few years. Her current symptoms include generalized fatigue and diarrhea, characterized as two to three semi-formed, nonbloody bowel movements each day and occasional episodes of watery diarrhea. Her bowel movements are usually precipitated by meals. She consumes a regular diet and has not recognized any intolerance to any particular foods. She denies having any abdominal pain, nausea, vomiting, recent travel, joint pain, rash, or change in the texture of her hair. She has been seen by several internists in her hometown, who have not provided her with a specific diagnosis.
Her medical history is significant for anemia, anxiety, and depression. Menarche occurred at age 16. Her menstrual cycle has been regular, with bleeding noted to be only modest. Her medications include oral contraceptive pills. She has not had previous surgeries.
On examination, she appears well. She is afebrile, weighs 128 lbs, and is 63 inches tall. The physical examination is normal, including a rectal examination and fecal occult blood testing.
Routine laboratory tests are performed. Results:
- White blood cell count 3.88 × 109/L (normal 4.0–11)
- Hemoglobin 10.4 g/dL (normal 12–16)
- Hematocrit 34% (normal 37%–47%)
- Mean corpuscular volume 80.2 fL (normal 80–100)
- Mean corpuscular hemoglobin 24.5 pG (normal 27–34)
- Platelet count 365 × 109/L (normal 150–400)
- Sodium 141 mmol/L (normal 132–148)
- Potassium 4.2 mmol/L (normal 3.5–5.0)
- Chloride 107 mmol/L (normal 98–110)
- Alanine aminotransferase 22 U/L (normal 0–45)
- Glucose 66 mg/dL (normal 65–100)
- Blood urea nitrogen 6 mg/dL (normal 8–25)
- Creatinine 0.6 mg/dL (normal 0.7–1.4)
- Thyroid-stimulating hormone 2.860 mIU/L (normal 0.4–5.5)
- Red blood cell folate 539 ng/mL (normal 257–800)
- Vitamin B12 321 pg/mL (normal 221–700)
- Iron/total iron-binding capacity 21/445 μg/dL (normal 30–140, 210–415)
- Ferritin 5 ng/mL (normal 9–150).
1. Which of the following is the most likely cause of her diarrhea?
- Thyroid disease
- Functional bowel disease
- Gluten-sensitive enteropathy (celiac disease)
Given her constellation of symptoms (fatigue, neuropsychiatric changes, iron deficiency anemia, and diarrhea), celiac disease is the most likely diagnosis. Hyperthyroidism can cause diarrhea, but this is unlikely since her thyroid tests are normal. Functional bowel disease is a diagnosis of exclusion and usually has a more chronic, fluctuating course.
CELIAC DISEASE HAS VARIOUS PRESENTATIONS
Celiac disease has various presentations and therefore has been classified into several types1,2:
Classic disease is dominated by symptoms of malabsorption. The diagnosis is established by serologic testing, findings of villous atrophy on biopsy, and improvement of symptoms on a gluten-free diet. However, the presentation of celiac disease has changed, and now atypical presentations are more common in adults (see below). The reason for the change in presentation is not known, but some have hypothesized that it is related to an increase in breast-feeding and the later introduction of cereals into infants’ diets.
Celiac disease with atypical symptoms is characterized by extraintestinal manifestations with few or no gastrointestinal (GI) symptoms. Patients may present with iron-deficiency anemia; osteoporosis or vitamin D deficiency; arthritis; neurologic symptoms such as ataxia, headaches, or depression or anxiety; myocarditis; infertility; or elevated aminotransferase levels. As in classic celiac disease, the diagnosis is established with serologic testing, findings of villous atrophy on biopsy, and improvement of symptoms on a gluten-free diet.
Latent disease includes cases in patients with positive serologic tests but no villous atrophy on biopsy. These patients have no symptoms but may develop symptoms or histologic changes later.
Silent disease refers to cases in patients who have no symptoms but have a positive serologic test and villous atrophy on biopsy. These cases are usually detected via screening of people at high risk, ie, relatives of patients with celiac disease.
It is important that clinicians be aware of the various symptoms and presentations of celiac disease in order to make the diagnosis.