This report describes various clinical and micro-nutrient abnormalities that existed in a 47-year-old woman who underwent a jejunoileal bypass operation. She exhibited extensive electrolyte, mineral, amino acid, and vitamin deficiencies. Amino acid absorption tests indicated an inability to absorb essential amino acids, especially the branched-chain and aromatic varieties. Vitamin absorption tests indicated an inability to notably absorb folic acid, niacin, vitamins B6, A, and E; the fat-soluble beta-carotene (provitamin A) was not absorbed from the diet. A liver biopsy revealed that 80% of the tissue was filled with fatty cysts. The ensuing liver disease compounded with biochemical abnormalities due to the bypass, contributed to the patient's death.