Does Lactic Acid affect the gastrointestinal system?

[Kitsune06]

I would also second the IBS thing...

Awhile ago, strenuous biking (the 'chase,chase,chase' game w/hubby) combined with work/life/etc stress made for serious gastrointestinal problems. In addition to lots of bowel pain/problems (curled up in a ball in front of my computer or elsewhere) I also had (thanks to the stress) ulcers and had a hard time eating enough... and then problems absorbing enough... etc etc, long story short, I lost way too much weight and got sick way too often.
If you have ulcer/heartburn issues in addition, I'd almost second mimitabby's reccomendation of the avoision of rich foods, and try prilosec otc to see if the p-pump inhibitors in the medicine actually reduce the acid in both your stomach and (later on in digestion) the amt of abdominal pain you experience later.
Be careful to stay adequately hydrated- not just when riding, but all the time, too.

[BleeckerSt_Girl]

If you get lots of cramping and diarrhea after eating things like big salads with raw leafy stuff (lots of insoluable fiber), then IBS would be suspect.

[Kitsune06]

...but doesn't everybody?

[tulip]

First we give her asthma, now we've given her IBS!

Honey, you are not falling apart, trust me!

Did you have this problem prior to taking up cycling? Maybe things are just moving through better now, and after an adjustment period, will settle down.

But keep track of what you eat, your activities, and how it affects you. And see a doctor (again) if this keeps up.