Mystery Diagnosis: Diarrhea

The House Call Doctor tackles another medical mystery. 

Sanaz Majd, MD,
January 30, 2013
Episode #085

Page 2 of 2


  • Any recent travel? Daniel lives in Southern California and often vacations in Mexico. In fact, he made a trip there just five or six weeks ago. I want to know this since infections caused by certain bacteria in food and water, such as the famous E. Coli, can cause something called “traveler’s diarrhea.”

  • Any cold/flu symptoms? He does not have any nasal symptoms, sore throat, headaches, fever, or cough. Viruses don’t only attack our upper respiratory systems, they can also attack our gut and cause diarrhea.

  • Any medications? Daniel seems to be a pretty healthy guy in general. Besides a high blood pressure medication which he’s taken for 3 years without any side effects, he’s not on any other chronic medications. I ask this because certain medications can cause diarrhea as a side effect, such as metformin used for diabetes.

  • Any recent antibiotic use? Daniel says he went surfing in Mexico and developed an acute sinusitis as a result, and he was given a course of antibiotics when he returned from his trip. Doctors don’t like antibiotics for many reasons, and one of them is that it can cause a horrible infection in the colon called C. Diff Colitis. The infection is named after a bacteria that overgrows in the colon as a result of antibiotics killing off the good bacteria normally living there.

  • Any constipation in between the bouts of diarrhea? Daniels tells me he “wishes” he was constipated. A chronic illness called Irritable Bowel Syndrome (IBS) can cause alternating diarrhea and constipation.

Family History

Taking a good family history can give us a clue as to what can be causing some illnesses because many ailments have genetic components. I asked Daniel about his family, and he reported that his parents both suffer from high blood pressure but are also otherwise healthy. I then specifically asked him about a medical condition called Inflammatory Bowel Disease (IBD) which no one in his family thankfully has. This is an inherited condition that sometimes causes chronic diarrhea. Examples of IBD include Crohn’s Disease and Ulcerative Colitis.

The Physical Exam

Next, I did a focused physical exam and listened to Daniel’s heart and lungs, which sounded great, and pushed on his abdomen. He has very mild tenderness all over, not in one particular spot that coordinates with a specific organ in his body. Patients with diarrhea often present this way on exam.

Diagnostic Tests

Since he’s had so much diarrhea, I ordered some labs to make sure Daniel wasn’t dehydrated. Sure enough, his electrolytes (sodium and potassium) were a tad low, indicating some mild dehydration.

I also ordered some stool studies, to check for E. Coli and other bacteria since he did recently travel outside the country. Lastly, I tested him for that nasty C. Diff bacteria because he’s had recent antibiotic exposure. And sure enough, his stool came back positive for C. Diff! 

The Diagnosis

Daniel has C. Diff Colitis, a horribly unpleasant condition brought on by the antibiotics he took for sinusitis. C. Diff is serious, and can land patients in the hospital. If severe enough (and untreated), it can even cause death. 

The Treatment

Once that we know the cause of the symptoms, it’s really important that we treat this infection fast. Besides advising Daniel to increase his fluid intake, I gave him a prescription for a medication that kills off the C. Diff in his colon.

One week later, Daniel looked like a new man! His diarrhea had ceased, and his repeat stool sample no longer had C. Diff growing.

Case closed!

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Please note that all content here is strictly for informational purposes only. This content does not substitute any medical advice, and does not replace any medical judgment or reasoning by your own personal health provider. Please always seek a licensed physician in your area regarding all health related questions and issues.


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