The aim of this study is to examine the clinical and pathologic characteristics of collagenous colitis (CC) in children and adolescents. Seven patients (five females and two males, median age: 13 years, ranging from 4 to 16) were included. Four (of 7, 57%) patients presented with non-bloody watery diarrhea, one with alternating constipation and diarrhea with rectal prolapse, one with constipation, and one with normal bowel movement. Abdominal pain and weight loss were manifested in 80 and 40% patients, respectively. Two patients had celiac disease in remission. None of the patients took non-steroidal antiinflammatory agents. All patients had normal colonoscopy, but had typical histologic features of CC in colon biopsies. Four patients had clinical follow-up (24-75 months duration, median 54 months): three patients had no gastrointestinal symptoms upon follow-up, but one patient had continued symptoms of alternating diarrhea and constipation. Two patients had follow-up biopsies: one showed persistence of CC, and one had complete histologic resolution. We conclude that while CC is rare in children and adolescents, the clinical presentation is similar to adults, with a female preponderance, presentation with diarrhea and abdominal pain, and an association with celiac disease and other autoimmune disorders. However, compared with adults, children and adolescents are more likely to have weight loss and an atypical presentation including alternating constipation and diarrhea, constipation alone or normal bowel movements. Treatment is less standardized in children and adolescents with CC.