How do you know whether you’re lactose intolerant? What are the symptoms?
lactose is a disaccharide sugar, we can only absord monosacchrides from the gut into the bloodstream so we break all di, and poly sacchrides down with various enzymes. Without lactase, which is the enzyme for lactose, the sugar does not get absorbed, and is therefore available to intestinal bacteria futher down the GI track. Party time ensues with rapid bacterial growth, and accumulation of waste gas, cramping, bloating, pain and IIRC diarrhea. Different individuals have it do different degrees, and I seem to recall some cultural variation related to the amount of dairy products in use.
Lactose intolerance - Wikipedia. Scroll down to “diagnosis”.
Symptoms: My sister’s tummy puffs up like a balloon, she farts like a bear, and then gets diarrhea.
(Um… meaning when she consumes dairy. If anyone else consumes dairy, it doesn’t affect her. I just worded it in a way that sounds like in anyone eats dairy, my sister’s tummy… oh, never mind.)
To diagnose it, she didn’t consume any dairy for a few days, then drank a glass of milk… balloon, bear farts, diarrhea.
Then she tried the same experiment, but this time she took some Lactaid tablets first. Nothing happened, so it was a no-brainer.
We lactose-intolerants prefer to think of ourselves as Properly Weaned. 
In addition to what outlierrn said, undigested lactose can also pull water into the digestive tract, the reverse of the normal procedure, which can produce watery diarrhea. The gas that is formed by bacteria in the colon depends heavily on the makeup of those bacteria. Some species favor digesting the lactose, some fermenting it - the latter will create the gas.
So the usual symptoms are some combination of gas, bloating, cramping, farting, and diarrhea. This can start shortly after a meal and can last literally for days, until all the lactose is eliminated from the system. The farts are often extremely foul-smelling.
There are numerous confounding factors.
First, there are hundreds of possible causes of gas and/or diarrhea. Look for a consistent pattern after dairy foods, especially after foods that contain liquid dairy products.
Second, diarrhea immediately after a meal is probably not the result of the food eaten in that meal but from the gastrocolic reflex, the signal that is sent to alert the intestines to start peristalsis.
However, many people with irritable bowel syndrome not only find that they are lactose intolerant but also have problems with spasming of the colon (one of the old names for the problem) and this could look like lactose immediately causing symptoms. Some also will find it difficult to stop the spasming even after the lactose is gone.
There’s very little that can be done to reduce the symptoms once they start. Lactase pills may help digest any lactose still not fermented, but they are not a panacea. Regular anti-diarrheals won’t help, since they keep the lactose in the system longer. (Although they may work later on to control excess spasming.)
Vomiting is not a symptom of LI, except in infants. Neither is heartburn or any other stomach symptoms. LI is a product of the intestines only.
You fart like a bear too, huh?
I haven’t been around enough bears to know… but try feeding milk to an old dog sometime and you’ll get the idea.
On second thought, don’t… it’s not a nice thing to do to the dog…
I’m lactose intolerant (this is a recent development). I don’t have the farty gas mentioned above. I get burpy and bloated and sometimes pukey sick feeling - like I have a touch of the flu. It lasts for several hours after drinking milk.
The runs.
What’s “a touch of the flu”? I don’t think I’ve ever vomited from the flu. I don’t think gastric upset is in general a symptom of influenza.
Fast for a day.
At the end of the day, drink 16 ounces of whole milk.
If you have had no bowel movements or wind within the next 2 hours after finishing the milk, you’re not lactose intolerant.
That’s what the doctor told me, anyway… I lasted all of 14 minutes after the test.
Are there degrees of Lactose intolerance? I get gassy when drinking milk but not with cheese, yogurt or ice cream.
Seven could be thinking of the so-called Stomach Flu (Viral Gastroenteritis):
Anecdotal, with the usual IANAD disclaimer: I can handle cheese (but do better with aged cheeses than fresh), butter, milk that has been cooked (as in cream sauces); I can’t handle drinking milk straight, and I have to be very careful with ice cream. I like ice cream, but I can only eat a little and I will suffer for it, but sometimes it’s worth it.
Worst case, for me, was after I had two bowls of cereal with milk as a snack one night. I don’t usually eat cereal, because milk has always made me gassy and crampy, but I had a craving. I spent the next three days in the hospital. Never been in so much pain in my life. After a battery of tests that had doctors scratching their heads, I finally had a BM and felt loads better. I asked my doctor if it could be lactose intolerance, and he said if it was, he’d never seen a case that bad before.
I was never diagnosed by a doctor, but I’m the observant sort, and I experimented a little. I reported my results to my doctor, and his opinion was that if I was having a bad reaction to milk, I should stay away from milk
Very much so.
The wife has a friend who would have crapped her pants if she did the test my doctor recommended. ANYTHING can set her off, although of course if the quantities are small enough, not a whole lot of trouble results.
Yeah, there are degrees. It’s due to your body not producing lactase to break down the lactose. Some people still produce a bit of lactase and can still break down some, but not all, of the lactose they eat. They might just get a bit burpy and bloated. Others like my sister, get pretty distressed within a couple hours of eating dairy (painful bloating, bear farts etc.).
My mom is only a touch lactose intolerant. My sister is BIG TIME.
Yogurt with live bacterial cultures is often okay because the bactria take on the lactose-break-down job. Old cheese is often okay in moderation too. I think the harder the cheese the less lactose. And fermented cheeses. My sister can eat huge quatities of cows mil feta with no ill effects.
hmmmmmmmmmmm Feta feta feta foreva
“Aged Swiss” from the local Amish-style market is 100% good in my system. I can have a sandwich with 5 of the solid-board-like slices of cheese they sell in and have not a bit of trouble.
Feta, I still get some distress from.
I wish I could find something besides aged Swiss that was consistently safe. Sharp cheddar isn’t.
Lactose intolerance often shows up in a person’s 20’s. Hit me my second year of college - I couldn’t figure out WHY I was so darn sick! I was living on Pizza, ice cream and cheese and crackers…
I’m in the severly affected group. I can occasionally deal with a little goat cheese, and the lactose free milks are great. Yes, I have vomited if the gut cramps get bad enough - but I think that is a reaction to extreme pain. (Timely topic - I just got an invite to a friend’s house for pizza - I think I’ll pass!)