Signs and symptoms	Pathophysiologic mechanism	Laboratory abnormalities
Gastrointestinal
Diarrhea	Malabsorption of fat, carbohydrate and protein	Stool weight >200 g
		Stool weight decreased to normal with fast
Weight loss	Nutrient malabsorption	Increased stool fat, decreased serum proteins
Flatulence, borborygmi, abdominal distention, foul-smelling stools	Bacterial fermentation of malabsorbed carbohydrates and proteins
	Increased flatus production
Bulky, greasy stools	Fat malabsorption	Increased stool fat, low serum carotene level
Hematopoietic
Anemia	Iron, pyridoxine, folate and vitamin B12 deficiencies	Microcytic, macrocytic or dimorphic anemia
Hemorrhagic diathesis	Vitamin K deficiency	Prolonged prothrombin time
Musculoskeletal
Bone pain (osteopenic bone disease)	Calcium, vitamin D and protein malabsorption	Hypocalcemia, hypophosphatemia, increased serum alkaline phosphatase level
Tetany	Calcium, magnesium, vitamin D malabsorption	Hypocalcemia, hypophosphatemia, increased serum alkaline phosphatase level, hypomagnesemia
Endocrine
Amenorrhea, infertility, impotence	Malabsorption with protein-calorie malnutrition	Low serum protein levels; may have abnormalities in gonadotropin secretion
	Probable vitamin D and calcium deficiencies	Increased alkaline phosphatase, increased serum parathyroid hormone
Skin and mucous membranes
Cheilosis, glossitis, stomatitis	Iron, riboflavin, niacin, folate and vitamin B12 deficiencies	Low serum iron, folate and vitamin B12 levels
Purpura	Vitamin K deficiency	Prolonged prothrombin time
Follicular hyperkeratosis	Vitamin A deficiency	Low serum carotene level
Scaly dermatitis or acrodermatitis	Zinc and essential fatty acid deficiencies	Low serum or urinary zinc level
Hyperpigmented dermatitis	Niacin deficiency
Edema and/or ascites	Protein malabsorption	Hypoalbuminemia
Nervous system
Xerophthalmia and night blindness	Vitamin A deficiency	Decreased serum carotene level
Peripheral neuropathy	Vitamin B12 thiamine deficiency	Decreased serum vitamin B12 level