Small bowel Crohn's disease neglected by gastroenterologists and anorectal surgeons with a 7-year delay in diagnosis: A case report.

RATIONAL: Small bowel Crohn's disease (SBCD) is a common site of Crohn's disease (CD). However, owing to the anatomical characteristics of the small bowel and the limitations of traditional examination methods, the detection and diagnosis of SBCD remain difficult. Gastroenterologists and anorectal surgeons should pay more attention to improving the early diagnosis rate, so as to improve the prognosis of patients and reduce the probability of surgery due to complications.

PATIENT CONCERNS: Here, we presented a case of a young male with severe localized pain in the right kidney area and fever but no weight loss or diarrhea, who had a history of perianal abscess surgery 7 years ago and an elevated platelet count reviewing his previous medical examination report.

DIAGNOSES: SBCD was not diagnosed until complications of intestinal fistula developed 7 years after perianal abscess surgery.

INTERVENTIONS: Anti-infection treatment was administered due to elevated inflammatory markers and evidence of infection on computed tomography scan, and exclusive enteral nutrition (EEN) was then performed because of the diagnosis of SBCD. Although the infection was absorbed by the treatment with EEN, a laparoscopic modified partial enterectomy was finally performed due to the complication of intestinal fistula.

OUTCOMES: The patient was discharged on the seventh postoperative day without postoperative complications and started biologic therapy 2 weeks after surgery because he had high-risk factors for postoperative recurrence. The pathological report revealed the involvement of the ileum in CD, and confirmed the existence of the intestinal fistula.

LESSONS: Gastroenterologists and anorectal surgeons should be aware that perianal abscess could be the first manifestation of SBCD; even if typical CD manifestations are absent, proper further examinations are necessary based on the comprehensive analysis of clinical data of patients. In addition, the platelet count deserves attention in patients with potentially possible CD. More importantly, it is important to emphasize the importance of EEN in adult CD patients.