Malabsorption syndromes: Pathology review

At the gastroenterology clinic, there is a 53 year- old man from the United Kingdom, named George, who came in complaining of periodic foul-smelling, bulky and frothy stools, as well as recurrent abdominal pain after meals and weight loss, despite not dieting.

On further history, he admits that he has been consuming alcohol with almost every meal for the last 10 years.

An upright abdominal x-ray shows calcifications in the epigastric area.

Next to him is a 9 year- old girl from Iran, named Yasmin, whose parents are concerned about her short stature and inadequate weight gain despite following a balanced diet.

On examination, her height and weight are below the 3rd percentile for her age and sex.

She also has an itchy rash consisting of small vesicles on both of her knees.

At first glance, you’d think George’s and Yasmin symptoms have nothing in common.

But the fact is, they both have different forms of malabsorption syndromes.

With malabsorption, nutrients are no longer effectively absorbed in the small intestine.

Nutrients can either be macronutrients, such as fats, proteins and carbs or micronutrients like vitamins and minerals.

Malabsorption can either be global, meaning that the absorption of all nutrients is affected, or it can be partial, meaning that only specific nutrients cannot be absorbed.

In general, unabsorbed nutrients are allowed to linger in the gastrointestinal lumen for longer than usual, disrupting the proper formation of stool, which results in diarrhea, bloating and flatulence.

And since these nutrients are lost in the stool, malabsorption will also lead to unintentional weight loss and various nutritional deficiencies.

For macronutrients, let’s start big, with fat malabsorption which causes steatorrhea, meaning fatty, greasy, floating, voluminous and terribly smelling stools.

And it’s important to know that screening for fat malabsorption is done with a fecal fat test, known as Sudan III stain.

A high yield fact to remember is that there will also be a decrease in the absorption of the fat-soluble vitamins; A, D, E, and K, and that might be the only clue you get for fat malabsorption!

So, in a question stem with symptoms like night blindness, eye dryness, corneal ulcerations or thickened skin, think of vitamin A deficiency.

In a child with rickets or an adult with osteomalacia there’s vitamin D deficiency.