Algorithm for the initial evaluation of an infant or child with rectal bleeding

CBC: complete blood count; CRP: C-reactive protein; ESR: erythrocyte sedimentation rate; INR: international normalized ratio; LGI: lower gastrointestinal tract; PT: prothrombin time; PTT: partial thromboplastin time; UGI: upper gastrointestinal tract.

* Refer to UpToDate topics on shock in children.

¶ Rarely, hematochezia (bright red blood per rectum) can be caused by UGI bleeding, especially in an infant (due to short intestinal transit time), or because of a massive UGI bleed in an older individual.

Δ The evaluation varies with the age and clinical presentation of the patient. For those with more than minimal bleeding or who are ill appearing, initial laboratory tests include a CBC with differential, ESR, CRP, basic metabolic panel, hepatic function panel, coagulation studies (PT/PTT/INR), and a urine analysis. If stools are loose or diarrheal, test stool for fecal calprotectin and enteric pathogens.