Diarrhea can be acute or chronic, and there are several disorders which can be a mixed picture. Often a patient reports having symptoms for a few days, which might make a clinician think that the patient has acute diarrhea. However, further information may reveal that diarrhea has been a recurrent problem with symptom free periods in between episodes. If a careful history is not taken to identify such a pattern, this may cause confusion and lead a clinician to an incorrect group of differentials. Therefore, a clinician must carefully ask questions about the duration and frequency (such as the pattern and previous episodes) early in the evaluation process. Some clinicians like to build probable diagnoses or differentials based upon the consistency of stools, which helps differentiate among the secretory, mal-absorptive, infectious causes of diarrhea. However, because patients often give very subjective description about consistency, this information may not be reliably helpful for a clinician to decide whether diarrhea is at all present.
Urgent/emergent situations involve the state of a severe volume loss or metabolic derangement resulting from diarrhea. These situations may happen in case of severe infections, especially in pediatric populations, drug toxicity, and/or inflammatory causes. These situations are reflected in a patient’s overall appearance of dehydration, distress, and abnormal vital signs.
Weighing and removing anchor bias involves asking high yield questions as described above and medium yield questions pertinent to each differential. The presence of fever, systemic symptoms and /or blood in the stool often point a clinician to an inflammatory or infectious etiology, whereas subtle, often chronic symptoms may reflect mal-digestive or mal-absorptive processes, although some symptom overlap may exist among pathologies. Acute episodes which correlate with the recent use of medicine, new food, and travel are usually recognized and described as such by patients, and therefore these correlations should be easy for a clinician to recognize. A complete gastrointestinal and general physical exam and lab and/ or imaging data should help a clinician arrive at the final diagnosis.