Twenty patients underwent placement of a jejunal catheter for early postoperative feeding at the time of upper abdominal operations, and a control group of 11 patients underwent operative procedures of similar magnitude without jejunostomy. Advancement of the rate of feeding to target intake over 6 to 7 days was attempted. Complications from the feeding led to cessation or curtailment of intake in 65 percent of the patients. Specific complications included abdominal pain and distention, diarrhea, and retrograde reflux of the feeding into the stomach. No statistically significant difference in nitrogen balance was demonstrated between the fed and unfed groups, presumably due to the limitations of nutrient delivery or absorption in the fed groups or elevated breath hydrogen excretion in patients with abdominal pain and distention suggests that the nature of the nutrients, particularly complex carbohydrates, is a factor in the development of feeding complications. Caution must be exercised in advancing the rate of postoperative jejunal feeding.