Crohn's disease is a type of inflammatory bowel disease, primarily affecting the terminal ileum and adjacent colon, but can involve any digestive tract segment from mouth to anus, displaying either segmental or skip distribution. Clinically, it is characterized by abdominal pain, diarrhea, weight loss, abdominal mass, fistula formation, and intestinal obstruction. It may also present with fever and extraintestinal manifestations, including joint, skin, eye, and oral mucosa damage. This disease tends to recur throughout a person’s life, and severe cases can be prolonged and unhealing with poor prognosis. The onset age is mostly between 15-30 years, but initial attacks can occur at any age. The incidence rate is similar between genders. Abdominal pain is the most common symptom, often seen in the lower right abdomen or around the navel, presenting intermittently as cramp-like pain accompanied by bowel sounds, typically worsening after eating, and relieved by defecation or passing gas. Diarrhea is another common symptom, initially intermittent but can become persistent in later stages of the disease, with stools generally being pasty and containing mucus and pus-blood. If the lower part of the colon or anorectal area is involved, there may be mucus-bloody stools and a sensation of incomplete evacuation after bowel movements. Abdominal masses are often located in the lower right abdomen and around the navel, and fistula formation is a characteristic clinical manifestation of Crohn's disease.