Thyroid hormones and the gut.

Thyroid hormones and the gut Thyroid hormones have an effect on the gastrointestinal tract at all levels of organization and clinicians have long recognized the associations that exist between gastrointestinal symptoms and thyroid disease. Our present know- ledge of the mechanisms by which thyroid hormones act on the gut is, how- ever, fragmentary and much of the literature which deals with disturbances in gastrointestinal physiology in hyper-and hypothyroidism is inconclusive." 2 This review is brief and makes no attempt to be comprehensive. It is intended to illustrate some aspects of the effects of altered thyroid function on the gastrointestinal tract rather than to dwell on the biochemical role of thyroid hormones at the cellular and subcellular level-a subject recently reviewed elsewhere.3