Patients with Chronic Diarrhea: Letter

Folate deficiency is almost invariably present in patients with untreated celiac disease, and antiendomysial antibodies are present in 90 to 100 percent of them.2,3 Furthermore, the concentrations of red-cell folate and serum B12 are often abnormal in patients with Crohn's disease and are useful indicators of the need for subsequent investigation of the small bowel. In the stepwise approach suggested by the authors, a small-bowel biopsy is performed as a second-stage investigation. [...]patients with celiac disease would already have undergone thyroid-function testing, serum gastrin measurement, and plain abdominal radiographic and barium studies of the upper gastrointestinal tract, small bowel, and colon before the correct diagnosis was made. Dr. Eisenberg suggests performing an enzyme-linked immunosorbent assay of the stool for giardia antigen in the first stage of the evaluation.