Background: Chronic diarrhea is one of the most common causes of referral to a gastroenterology clinic. Chronic diarrhea may result from many different causes; celiac disease is one of them. Other important causes in our locality are infections such as TB and Giardiasis. Aim of the work: This work was planned to: 1- Determine the frequency of celiac disease, TB enteritis and Giardiasis among children referred to the gastroenterology unit with the complaint of chronic diarrhea and to evaluate the different methods used in the diagnosis of each disease. 2- Verifying the diagnostic accuracy of immunohistochemical tTG expression versus serum anti-endomysial antibodies (EMA) in celiac disease (CD) mucosa.
Subjects and methods: The study included 92 patients with chronic diarrhea. Their ages ranged from 6 months to 15 years. They were 56 males and 36 females, admitted to the Pediatric Gastroenterology Unit, Assiut University Hospital during the period from January 2005 to December 2006. Besides full history and thorough clinical examination, the following investigations were done for all cases: stool analysis for three consecutive days, CBC, ESR, total proteins and serum albumin, tuberculin test, accelerated BCG test (in tuberculin negative cases), serum anti-EMA. Upper GIT endoscopy with duodenal biopsy and aspiration and tissue staining by H&E and by Immunohistochemical (anti-tTG moAbs) to detect tTG antigens in biopsy specimens. Lower GIT endoscopy with biopsy sampling and histopathological examination of biopsy specimens was also done. Results: Out of the total patients, 18 cases (19.5%) were positive for celiac disease AEM antibodies while 16 were positive by tTG immunostaining of biopsy specimens. Fourteen patients (15.2%) had tuberculous enterocolitis while 12 (13%) had biopsy proven Giardiasis. On the other hand 48 patients (52.1%) had other undiagnosed causes of chronic diarrhea.
Conclusions and recommendations: A very high index of suspicion for CD should be maintained for patients who present with chronic diarrhea or iron deficiency anemia. The best method for diagnosis of celiac disease in such patients is serological testing followed by a small-bowel biopsy. The diagnosis of intestinal tuberculosis is difficult due to the lack of specific symptoms and signs. Colonoscopy with ileoscopy is a useful method for diagnosis of intestinal TB. Gastrointestinal endoscopy with biopsy examination is an important method of diagnosis and follows up of children with Giardiasis.