Clinical manifestations: diarrhea, occasionally bloody; abdominal pain over the site of maximum inflammation; fever and malaise, malabsorption syndrome.
Diagnosis:
Physical examination: palpable mass (matted bowel loops due to transmural
inflammation in Crohn disease); a fistula is often detectable
Sonography
High colonoscopy with ileoscopy and tissue sampling from all bowel segments
(Crohn disease does not always produce grossly visible changes if it affects only the deep wall layers, and so generous biopsies should be taken in all suspected cases)
Gastroduodenoscopy may also be done, taking biopsies from the distal duodenum (Watson capsule biopsy may be obtained to evaluate for sprue).
Radiography : Double-contrast enema is necessary only if endoscopy cannot be done or the patient is believed to have diverticula.