The diagnosis of these infections can sometimes be suspected clinically. The poor guy with fever, lower abdominal cramps, and blood streaked diarrhea probably has shigella. And the one who has been passing gas that curls your nose for two months, might have giardia. But the definitive diagnosis rests with examination of the stools. It may be necessary to examine more than one specimen.
Treatment is based upon the causative agent, as well as the clinical state of the patient.
Antibiotics, such as Cipro and Noroxin, may be used for the treatment of bacterial infections. This condition may follow almost any bowel infection. It is usually transient. A lactose free diet may help, as might products such as Lactaid or Lacteeze. This diagnosis would require further investigations such as colonoscopy and bowel biopsy.