Constipation is a frequent gastrointestinal complaint in both adults and children that is commonly treated with lifestyle modification and laxative trials. Constipation may be idiopathic or secondary to another disease process. Initial evaluation of constipation in children and adults focuses on identifying alarm signs or symptoms that may be suggestive of (1) alternative diagnoses, (2) an underlying causative systemic disease, or (3) very rarely complications of constipation that may necessitate surgical intervention. Obstipation, involuntary guarding, rectal bleeding, fevers, and ill-appearance should prompt consideration of alternative diagnoses and necessitate early surgical consultation. In the absence of these features, systematic history-taking and physical examination are essential to identify patients with constipation who may benefit from a therapeutic laxative trial prior to early subspecialty referral. Perineal examination may identify congenital causes of constipation or sequelae of chronic constipation and inflammatory bowel disease. An abdominal plain film is a helpful adjunct to support the diagnosis of constipation and guide decision-making in patients with constipation refractory to initial laxative trials. Upfront cross-sectional imaging should be avoided in well-appearing children prior to surgical referral. In the absence of features concerning an anatomic cause of constipation, patients with constipation refractory to laxative trials merit referral to a gastroenterologist to guide next diagnostic and therapeutic steps. Findings concerning anatomic causes of constipation should prompt referral/consultation with an age-appropriate surgeon with colorectal expertise.