The hypothesis is that there are unique sonographic characteristics of antibiotic-associated diarrhea. We will compare the ultrasound findings in patients who received antibiotics and developed diarrhea to toxin analysis for clostridium difficile in stool in order to find differences in the sonographic findings in the positive and negative cases.

Inclusion Criteria:

• admitted patients who developed diarrhea in 72 hours since the beginning of admission
• patients age above 18 years.
• patients received antibiotics during admission

Exclusion Criteria:

• other reasons of diarrhea
• drugs induced diarrhea
• length of time since the beginning of diarrhea is shorter than 72 hours.
• patients had diarrhea during the first day of admission

Patients in internal and geriatrics departments who developed diarrhea in a period of 72 hours since the beginning of admission and received antibiotics.