Warfarin absorption after massive small bowel resection.

Small bowel resection is often accompanied by malabsorption and nutritional deficiencies. Malabsorption of drugs may also occur; however, few reports have been published. We treated five patients with oral warfarin for thrombotic problems after substantial small bowel resection. All five had a documented hypoprothrombinemic response to the warfarin (patient prothrombin time: control greater than 1.5). Maintenance warfarin doses were up to 10 mg/day. Oral warfarin appears to be well absorbed after removal of the majority of the jejunum and ileum. This may indicate a proximal site of warfarin absorption.