Secondary Malabsorption--What's That?

Lactose or fructuse malabsorption can be secondary to another medical condition. What does that mean? Mirriam-Webster defines secondary as "Not first in order of occurence or development--dependant or consequent on another disease."

How could lactose malabsorption occur as a consequence of another disease? Well, to review, proper lactose absorption requires:

• production of the enzyme lactase by cells lining the small intestine
• time for the enzyme to break lactose down to glucose and galactose
• time for for the absorption of glucose and galactose
• healthy and large enough absorptive surfaces in the small intestine

There are any number of ways that other medical conditions, untreated, could cause secondary lactose malabsorption:

• Damage to the cells lining the small intestine can diminish lactase production and cause loss of absorptive surfaces. Damage or loss of healthy tissue in the small intestine could be caused by untreated celiac disease, Crohn's disease, a stomach virus, food poisoning, parasites, radiation therapy, a resection, etc.
• Anything that speeds up the rate at which food moves through the gastrointestinal tract (known as rapid transit time) can mean not enough time for lactase to do its work or not enough time for complete absorption of sugars. Picture this as a commuter train rolling through the station too fast to let off passengers! Intestinal transit time can be sped up by certain medications, ulcerative colitis, bile salt malabsorption or other food sensitivites or intolerances, to name just a few. Yes, this means that lactose malabsorption can occur secondary to fructose malabsorption (and vice versa), another reason the FODMAP approach is more effective in managing symptoms for some people than dealing with lactose or fructose malabsorption in isolation.

The scenario is similar for fructose malabsorption, except that fructose does not need to be digested before it is absorbed--there is no enzyme comparable to lactase involved.

The GOOD news about secondary malabsorption of lactose or fructose? If the underlying condition is treated, cured, healed, or in remission, absorption is much improved or even completely restored!

Comments

[Momma of a sensitive little guy]

Hi, How often is FM alone the main cause of GI symptoms and other problems? Or is it most often a secondary problem?
Thanks!

[Patsy Catsos]

Hi Momma, I don't have any stats on this. My impression from my practice is that it is relatively rare to have primary, stand-alone fructose malabsorption. It does seem to usually be part of a package of food intolerances. However, I realize I might have a skewed viewpoint because maybe people with primary fructose malabsorption are managing it perfectly well without needing to seek the help of a dietitian.

[Ram]

Hello Patsy, I purchased a copy of your pricesless book last week here in India and I must say I'm so glad I did! The elimination of FODMAPS has helped me tremendously, thank you very very much! Patsy, I have a question for you. After four years of gradual weight loss and soft stools, I found out that I have some form of IBD. There is no bleeding, my colonoscopies are normal and I do not suffer from pain. Bloating makes me quite uneasy but I cannot call it severe pain. The only way I found out I have some of IBD was after a comprehensive stool analysis (elevated lactoferrin,lysozyme and IgA). Doctors don't want to listen to me because my symptoms are not that severe and they think I'm losing weight just because I'm some sort of 'diet'. I have become fructose and lactose intolerant and it seems to be secondary malabsorption as you have mentioned above. I started out with the SCD about 2 months ago but that didn't help unless I had very little of everything. Since I have read your book and have followed it, I have felt better. However, I'm still not having any grains or sugar. Do you think I should go ahead and try adding oats/rice to my diet? I'm just too scared I must say. Please advise. Thank you so much again!

[Patsy]

Well I can't safely give you personal advice in this setting so I will give some general comments. One can theoretically get enough calories to prevent weight loss on a diet without grains and sugar by increasing portions of fats, meats, lactose-free milk products and the tolerated fruits and vegetables. Sugar doesn't do much for us nutritionally so no rush to add that back. Grains can offer nutrients, though, so I encourage trying the low FODAMP grains. When someone is too afraid to try an actual fructan challenge, or if one has another illness like an IBD, it makes more sense to just cautiously introduce small portions of the lowest-fructan foods from the bottom of the challenge list. I am so excited to have heard from my first Indian reader...Amazon recently notified me the book would be available there!