I've had this problem for many years, I've talked to a sports doctor, and a sports nutritionist about it.  They too are somewhat at a loss.  Their advice was to experiment with different foods, times when I eat, and eleminiate dairy the night before and day of.  And then try other things while running instead of gels.  After my third marathon I could no longer eat the gels etc...without losing it.  It also seems to be worse with running in the heat.  In the winter I don't have as many problems.  And it is worse when I increase my pace.  The doctor said that when my body gets used to the increase in pace it should work out but it will be a slow process.  Here is what I've done.

I get up and eat AT LEAST an hour before I am going to run, sometimes this is very early in the morning but I do it anyway.  I tried a lot of different things but find that oatmeal, a banana, or toast with a bit of peanut butter seem to be the best things.  NOTHING with dairy.  Although I have lots of friends that drink a cup of coffee to "stimulate" them so they can go to the bathroom, I can't do that.  But maybe it will work for you.  I usually have a BM before I go out, and sometimes more than one.  But even then occassionally I find that I still have an issue.  Someone else replied to you about watching what you eat and how late you eat at night and I agree with that as well.  For me if I eat lite and early it's better when I run in the morning.  I also have one friend who makes half a peanut butter sandwich at night, puts it by her bed, wakes up two or two and a half hours before she runs, eats, goes back to sleep and then gets up just in time to go to the bathroom and do her run.  So I think if you experiement with different foods and times the night before and an hour or more before you run you will eventually find the best for you.

As far as what to eat while running, I switched from gels to things like fig newtons, boiled and salted potatoes, pretzels, sometimes sports beans work.  I eat those and with water and a minimum amount of sports drink.  Someone else mentioned trying different sports drinks, I know a lot of people who are intolerant to some so maybe that is part of it.

The nutritionist I saw also mentioned not enough fiber in the diet, that seemed a little backwards to me, but I've tried to east more vegatables, fruits, and whole grains and that also seems to have helped.

I hope I was able to offer something that will help you.  It's a real pain and I know how you feel.  I too, like someone else who replied, take routes where there are potties available, and I take TP with me when I go for a long run.

Good luck!

Hi,

I just wanted to put in my two cents. I have had this problem. It was a complete mystery. I wasn't eating that morning, bland food early the evening before. No clue as to what could be wrong.

I had one doctor finally figure it out. My thyroid.

Yup, thyroid. I got it under control with some Synthroid and it hasn't happened again.

As women, our thyroid controls a lot of how our body functions. It isn't just our mood, our weight and our complexion, it is also our GI system.

Good luck to you. This is a terrible thing to deal with.

Hello~ I am a Registered Dietitian and specialize in sports nutrition and food intolerances.  First of all, if you haven't already you will want to try the following things: 1) Perhaps look into measuring your sweat rate so you can match your fluid intake with losses during exercise.  2) Avoid foods before exercise that commonly cause GI issues such as fructose, ibuprofen, artificial sweeneters, sorbitol, high fiber foods (like bran cereals, whole wheat items, beans, etc), high fat foods, and occassionally dairy.  I would NOT recommended a high fiber diet on the 1-3 days before a race.  3) My next suggestion may be a new one to you but you may want to look into gluten intolerance.  I have recently been working with many people that have one or more symptoms of gluten intolerance and their symptoms of GI issues (diarrhea, stomach sloshing, bloating, etc) have disappeared after removing foods that contain gluten.  I also have personal experience with gluten intolerance and am a runner/triathlete so know the struggles of dealing with GI issues during exercise!  If you want to email me personally for any other info or questions feel free to:) courtneyRD83@aol.com  Thanks.