Definition
A.Malabsorption syndrome is a group of signs and symptoms occurring as a result of digestive problems and absorption of nutrients. There may be a resultant decrease in absorption of fat-soluble vitamins A, D, E, and K. Poor absorption of carbohydrates, minerals, and proteins may also occur.
B.The presentation of malabsorption varies from severe overt symptoms with weight loss to discrete oligosymptomatic changes in hematologic/laboratory tests that are found incidentally. Malabsorption can result from congenital defects or from acquired defects, such as bariatric surgery, and may be either global or partial. The degree of nutrient malabsorption from bariatric surgery is dependent on the type of bariatric procedure.
Incidence
A.Incidence is unknown.
Pathogenesis
A.Deficiency of intestinal enzymes: Lactase deficiency.
B.Inadequate digestion caused by diseases of the pancreas (such as cystic fibrosis [CF]), gallbladder, liver, and biliary systems.
C.Change in bacteria that normally live in the intestinal tract.
D.Disease of intestinal walls, such as helminthes (worms) or parasites, tropical sprue, and celiac disease.
E.Surgery that reduces the intestinal tract, decreasing the area for absorption, such as bariatric surgery.
F.Intolerance to gluten, or celiac sprue.
G.Atrophic gastritis results in hypochlorhydria and achlorhydria. The body does not produce enough pepsin and hydrochloric acid to release the food-bound vitamin B12 from protein.
Predisposing Factors
A.Lactose deficiency:
1.Incidence is increased in African Americans, Indians, and Asians.
2.Jews typically have onset in adulthood.
B.Family history of malabsorption or CF.
C.Use of drugs, such as mineral oil or other laxatives.
D.Excess alcohol consumption.
E.Travel to foreign countries.
F.Intestinal surgery:
1.Partial or total gastrectomy.
2.Small bowel resections (jejunum, ileum, ileocecal).
3.Partial or total resection of the pancreas.
G.Chronic pancreatitis:
H.Advanced age (increased risk for malabsorption and malnutrition).
I.Long-term adherence to a strict vegetarian or vegan diet (exclusion of all forms of animal protein, including eggs and dairy products).
J.HIV infection.
Common Complaints
A.Diarrhea, stools pale, greasy, and copious.
B.Foul-smelling stools, frequently with mucus.
C.Weight loss despite adequate food intake.
D.Gas or vague abdominal discomfort.
E.Anorexia.
Other Signs and Symptoms
A.Early malabsorption:
1.Minimal weight loss.
2.Softer, more frequent stools.
3.Steatorrhea; stools float
because of increased trapped gas.
4.Abdominal discomfort.
5.Bloating.
B.Later signs: Symptoms mentioned plus the following:
1.Marked weight loss.
2.Foul-smelling, bulky, greasy stools.
C.Malabsorption of fats and carbohydrates: Previous symptoms plus the following:
1.Foul-smelling, bulky, greasy, sticky
stools that may be difficult to flush down the toilet.
2.Ecchymosis.
3.Bone pain.
4.Glossitis.
5.Muscle tenderness.
6.Cramping in lower abdomen after bowel movement (BM).
D.Malabsorption of lactose:
1.Nausea and bloating.
2.Cramps.
3.Diarrhea after ingesting more than customary intake of milk products.
4.Absent or mild weight loss and steatorrhea.
5.Good appetite.
E.Edema: With severe protein depletion/calorie malnutrition.
F.Ecchymosis and bleeding disorders secondary to vitamin K malabsorption.
G.Vitamin malabsorption:
1.Generalized motor weakness (pantothenic acid, vitamin D).
2.Peripheral neuropathy (thiamine).
3.Sense of loss for vibration and position (cobalamin).
4.Night blindness (vitamin A).
5.Seizures (biotin).
Subjective Data
A.Review onset, duration, and course of symptoms. Are there any other family members with the same history/symptoms?
B.Ask the patient about dietary intake history.
C.Review any changes in BMs and stool characteristics.
D.Inquire about recent travel to areas known for giardiasis or other parasites.
E.Document weight loss, how much, and over what period of time.
F.Review previous gastrointestinal (GI) surgery, including bariatric procedures and reversals, small bowel resections, and partial or total resection of the pancreas.
G.Ask the patient about signs and symptoms of inflammatory bowel disease (IBD), such as easy bruising, paresthesia, and sore tongue.
H.Ask about any irradiation treatment.
Physical Examination
A.Check pulse, respirations, blood pressure (BP; may have orthostatic hypotension). Check height and weight to calculate body mass index (BMI) in order to follow serial weight loss.
B.Inspect:
1.Observe general appearance, noting wasting and apathetic appearance.
2.If the patient experiences a BM after the examination, observe the stool for volume, appearance, presence of blood, mucus, and the presence of gross worms/parasites.
3.Inspect the skin for ecchymosis, jaundice, pallor, surgical scars, stigmata of hyperthyroidism or hepatocellular failure, or signs of Kaposi’s sarcoma. Alopecia or seborrheic dermatitis may be present.
4.Inspect the ears, nose, and throat for glossitis, stomatitis, aphthous ulcers, poor dentition, and goiter.
C.Auscultate:
1.Auscultate the heart for tachycardia.
2.Auscultate the abdomen in all four quadrants for bowel sounds, noting borborygmi.
D.Percuss abdomen.
E.Palpate:
1.Palpate all lymph nodes; look for lymphadenopathy.
2.Palpate the abdomen for organomegaly, focal tenderness, masses, distension, and ascites.
F.Neurologic exam: Assess for signs of vitamin B12 deficiency, including motor weakness, peripheral neuropathy, or ataxia.
G.Rectal exam: Note tenderness, discharge, blood, and stool.
Diagnostic Tests
A.Assessment of stool fat: Qualitative assessment on a single specimen.
B.Quantitative assessment of a 72-hour stool collection while the patient is following a 100 g of fat diet.
C.Increased fecal fat: Test for celiac disease.
D.Abdominal ultrasound.
E.Colonoscopy to evaluate and obtain biopsies.
F.Endoscopy to evaluate and obtain biopsies.
G.Barium studies.
H.Consider CT of the abdomen.
I.Endoscopic retrograde cholangiopancreatography (ERCP) helps to document malabsorption due to pancreatic or biliary-related disorders.
J.Breath tests for carbohydrate malabsorption.
K.Complete blood count (CBC) and electrolytes.
L.Serum iron, vitamin B12, and folate concentrations.
M.Prothrombin time (PT): May be prolonged due to vitamin K deficiency.
N.Vitamin levels: Vitamins A, D, E, and K may be decreased.
O.Total protein: May be decreased.
P.Albumin: May be decreased.
Q.Serum amylase.
R.Stool for ova and parasites; obtain on alternate days for three or more specimens because parasites are passed intermittently.
S.Serum immunoglobulin A (IgA)—used to rule out IgA deficiency.
T.Three-stage Schilling test (vitamin B12 deficiency) identifies the cause of B12 deficiency. However, it is rarely used now due to B12 and methylmalonic acid availability. The administration of oral or injectable B12 is commonly ordered.
Differential Diagnoses
A.Malabsorption.
B.AIDS.
C.Alcoholism.
D.Worms or parasites.
E.CF.
F.Celiac disease.
G.Failure to thrive (FTT).
H.Crohn’s disease (CD).
I.Tropical sprue.
J.Side effect from bariatric surgery.
K.Disaccharidase deficiencies (lactase).
L.Fructose intolerance.
M.Lactose intolerance.
N.Milk or protein allergy.
O.Whipple’s disease.
P.Zollinger–Ellison syndrome.
Q.Chronic pancreatitis.
R.Cirrhosis.
Plan
A.General interventions: Treatment depends on underlying cause.
B. 
See Section III: Patient Teaching Guide Lactose Intolerance and Malabsorption.
C.Dietary management: In most patients, diet modification or dietary supplements restore health.
D.Pharmaceutical therapy:
1.Vitamin supplements: Fat-soluble vitamins A, D, and K are most likely to be depleted. Supplements help prevent malnutrition, even though caloric intake may be replenished:
a.Vitamin A: 25,000 to 50,000 U/d orally.
b.Vitamin D: 30,000 U/d orally.
c.Vitamin K: 4 to 12 mg/d orally.
d.Vitamin B12: 1,000 g/mo by IM injection.
2.Enzyme replacements: These replace endogenous exocrine pancreatic enzymes and aid in digestion of starches, fat, and proteins. Pancreatic supplements are typically expressed in U.S. Pharmacopeia Convention (USP) units. One international unit (IU) is equivalent to approximately two to three USP units:
a.Pancreatin: Doses vary with the condition being treated. Oral doses are given before or with meals or each snack. They may also be given in divided doses at 1- to 2-hour intervals throughout the day. Use with extreme caution for patients with a known hypersensitivity to pork products:
i.Malabsorption syndrome—8,000 to 24,000 USP units of lipase activity occasionally up to 36,000 units of lipase activity may be required. Considerable dosage variation exists, partly due to the susceptibility of pancreatin to acid–peptic inactivity in the upper GI tract.
ii.Functional indigestion—1,200 to 2,400 USP of lipase activity.
b.Pancrelipase (Creon, Pancrease, Ultrase, Viokase): This must be given with each meal or snack:
i.Adults: One to three capsules or tablets orally with meals; titrate dose to desired clinical response.
3.Antispasmodics:
a.Anticholinergic agents are used to reduce the cholinergic stimulation of colonic activity that occurs in response to a meal.
b.Drug of choice: Dicyclomine hydrochloride (Antispas), 10 to 20 mg orally before meals.
4.Iron and folic acid supplementation are usually required for celiac disease.
5.Calcium and magnesium supplementation are required after extensive small intestinal resection.
6.Antibiotic therapy for bacterial overgrowth.
7.Corticosteroids and anti-inflammatory agents to treat regional enteritis.
Follow-Up
A.If exam is normal, observe the patient for 1 month and have the patient keep a diary of food intake and weight.
B.For persistent malabsorption, monitor for osteoporosis/bone mass with a dual-energy x-ray absorptiometry (DEXA) scan.