Steatorrhoea and fat malabsorption

What it is

Steatorrhea is the stool of maldigestion, and it marks exocrine pancreatic insufficiency. In chronic pancreatitis it appears only when more than 90% of function is lost, so it is a late sign rather than an early one.

Causes and risk

Chronic pancreatitis is the main pancreatic cause, and its etiology is grouped by the TIGAR-O classification (Toxic-metabolic, Idiopathic, Genetic, Autoimmune, Recurrent acute pancreatitis, Obstructive), which is the standard etiologic framework; chronic alcohol abuse is the most common cause in industrialized countries. Cystic fibrosis is the other main cause: pancreatic insufficiency with malabsorption and steatorrhea and fat-soluble vitamin deficiencies (A, D, E, K), and malabsorption is the presenting problem in about 30%, as steatorrhea and failure to thrive. Outside the pancreas, patients with steatorrhea should be evaluated for small-bowel malabsorption disorders such as celiac disease and for bacterial overgrowth. A drug can do it too. Orlistat is a lipase inhibitor given as 120 mg PO TID before meals, with an OTC dose of 60 mg PO TID, and steatorrhea heads its side effects, with fecal urgency, incontinence, flatulence, oily spotting, frequent bowel movements, abdominal pain and headache. Eating more than 30% kcal from fat results in greater GI side effects. It is contraindicated in pregnancy and breastfeeding, in chronic malabsorption syndrome, in cholestasis and in oxalate nephrolithiasis, and because it causes malabsorption of fat-soluble vitamins a standard multivitamin including vitamins A, D, E and K is recommended at bedtime or 2 hours after the dose. Levothyroxine and orlistat are administered 4 hours apart, and its effects on other medications are listed as warfarin (enhance), anti-epileptics (decrease), levothyroxine (decrease) and cyclosporine (decrease).

Celiac disease is the small-bowel cause to name in full. It is an autoimmune disorder characterized by intestinal hypersensitivity to gluten, a grain protein such as wheat, and it is associated with other autoimmune diseases, especially Sjögren's, thyroid disease and DM Type1. In chronic pancreatitis the causes named are alcohol, which is the most common, and cystic fibrosis.