I'm a 29 y/o male. For 3+ years now I've head diarrhea and upset stomach that is caused primarily by starch and sugars. I figured this out by trial and error during the first few months. First, by attempting to go on a BRAT diet during a period of gastrointestinal distress. That made it worse. It seems to be that certain things make it much worse - peaches, apples, bananas... fruits are probably the worst offenders. Breads and lactose-containing foods don't sit well either. I do not know if it's relevant but the year prior to this all starting I had taken antibiotics (Clindamycin twice, and Erithromycin once) for tooth infections and eventually post-operative wisdom teeth removal. I had 2-3 bouts of gastroenteritis with this problem occurring after the third bout of gastroenteritis. That happened during a business trip to California. No fever during the time that I can recall, just weird diarrhea with undigested food and then a slow not full recovery.
The exact result of eating starchy and sugary food is gastrointestinal distress 3-5 hours after eating. Typically, this involves bloating and strong cramping with some gas. If severe enough I'll feel sweaty, tired, and need to lay down. After about an hour of this it will normally go away. Later, when I have a bowel movement it will be very loosely formed, sticky, and irritate the skin from my butt. I'll usually need to go to the bathroom often during the day if I've eaten many carbs and it will feel incomplete. If I don't stop eating carbs I can get some leakage. I haven't seen any blood.
As a result of this I was on a very low carb ketogenic diet for the last 2 and a half years. This made everything manageable and I had some additional fiber plus a large number of vegetables daily for a while to do normal, daily solid bowel movements with all the protein and fat I was eating.
I've been to a 2 gastroenterologists. I tested negative for lactose and fructose intolerance. I had a hydrogen breath test and tested negative for SIBO. I have not had a methane breath test - doctor doesn't believe in it. Blood tests - negative for celiac. Stool tests - negative for bampylobacter, shiga, leukocytes, giardia, ova, salmonella/shigella,
I had an upper endoscopy with biopsy - it showed negative for helicobacter and negative for celiac. Mild chronic inflammation in my stomach (mild gastritis). They found I have a very minor hiatal hernia as well.
Probiotics have not helped. I tried VSL#3, florastor, and Align. Prescription enzymes did not help. 550mg Xifaxin for a week showed no improvement. My gastroenterologist asked me to add rice into my diet. I found I could tolerate BROWN rice and sweet potatoes and added them in. Additionally, sugary drinks with no food seem to not cause issues. I guess my small intestine just absorbs the carbs before whatever issue can arise. Sweet potatoes caused hives at first, but didn't again later. More recently, I have had an issue with dryness of mouth/nose/lips and eye irritation that seems proportional to the amount of carbohydrates I eat. I don't have diabetes, but I tested blood sugar just to make sure... it has not been excessively high ~110 I've seen occasionally a bit after eating. Adding carbs has recently made my stomach symptoms significantly worse and more sensitive to carbs. However, being on low carb for so long has irritated my thyroid or something else. Trying to switch back to low carb caused extreme fatigue, coldness etc. that's gone on for a couple months. This gets somewhat better adding carbs back in but then I deal with terrible digestion and possible immune problems (eye irritation, dryness, etc.). I'm stuck in this limbo now pretty scared.
I'm looking for ideas on what angle to pursue with the carbohydrate digestion issue. The immune angle is interesting but my c-reative protein has been normal, and wbc's and eosinophils are within range. There's this "leaky gut" idea out there but it seems like a fringe alt-med thing.
I need help :( Should I be seeing an infectious disease specialist for the digestion issues? Any ideas on what to do? When I eat carbs it really feels like everything is getting much much worse, but when I don't I can't handle the fatigue. I'm going to see an endocrinologist for the fatigue but not until Sept. I have a colonoscopy scheduled for October.