In a 37-year-old woman with chronic watery diarrhea of three years duration, the diagnostic of collagenous colitis was established by optical and ultrastructural examination of rectal and colonic biopsies. No other cause of diarrhea could be found. Moreover, this patient had also selective IgA deficiency, Grave's disease and chronic atrophic gastritis of auto-immune type. Sequential treatments with loperamide, cholestyramine and antibiotics did not modified diarrhea which improved with salazosulfapyridine and betamethasone enemas. These observations suggest that collagenous colitis might be a part of the spectrum of enteropathies associated with immunoglobulin deficiencies.