Dark Stool, Usually have IBS

I'm a 24 years old male and for about a few years already every 2 months (sometimes less some times more) I will get intense pain in my lower abdomen followed by diarrhea (usually at night). The stools are loose with an intense odor (color normal however, not black nor red). It may take up to three times before I feel the "relief" and then feel fine however, I will feel a little woozy for the next day or so (tiredness). This is usually after a period of stress or a change in my diet (after a month or so I somewhat forget the last episode and start eating all kind of junk food and then BAM! After a week or more of eating junk food I will get this again).

Other than that I feel great, no weakness or nothing special to mention. My doctor said it's probably very mild IBS and shouldn't worry about it too much if when I keep a good diet, this doesn't happen. However, I am a little worried. The other day I was feeling nauseous and was very constipated so I decided to take a pepto bismol (1 pill). It passed however for the past 2 days I've been passing stool with some dark "parts". Now I've read about pepto bismol might be cause this however, for how long is it suppose to last? What would be the "alarm" symptoms I should consider? I don't feel feverish, I'm not tired, I exercise every 3 days or so. If it was something more "dangerous" would I feel any other symptoms? To be honest the mentioned test don't really appeal to me however, I don't want to take stupid risks so I want to know when I should go pass more tests.

[Kevin Pho, MD]

IBS is certainly possible given the diarrhea and constipation as well as abodominal pain.  The "red flag" symptoms would include the presence of blood and weight loss.

To further evaluate this, a lower endoscopy can be considered - such as a colonoscopy or flexible sigmoidoscopy.  If negative, an abdominal CT scan can be considered.  These tests can evaluate the other possible causes - such as inflammatory bowel disease, cancer, or colitis.  

These options should be discussed with your personal physician, or in conjunction with a gastroenterologist.

Followup with your personal physician is essential.

This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.

Kevin, M.D.
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