Case Report: Extensive colonic necrosis and perforation in an HIV patient with syphilis complicated by sepsis.

Background: 'Soluble' total colon necrosis is a rare condition with an unclear etiology and few reports on treatment modalities. This case report describes severe intestinal necrosis in an HIV-infected patient, detailing clinical manifestations, diagnostic process, treatment regimen, and outcomes, thereby providing a reference for similar cases in the future. Case description: The patient is a 41-year-old man diagnosed with HIV 6 years ago, receiving long-term therapy with tenofovir, lamivudine, and efavirenz. He has no history of smoking, alcohol consumption, inflammatory bowel disease, or intestinal tuberculosis, but has had multiple sexual partners. He was admitted with 3 h of abdominal pain; a blood pressure of 108/76 mmHg; a heart rate of 148 bpm, and physical findings of generalized abdominal tenderness, rebound tenderness, muscle rigidity, and diminished bowel sounds. Laboratory results showed elevated procalcitonin (5.15 ng/mL), white blood cells (9.2 × 10^9/L), and C-reactive protein (232.10 mg/L). Abdominal CT revealed thickened walls in the ileocecal region, colon, and rectum, with small bowel dilation, gas, and fluid accumulation, indicating hollow organ perforation and diffuse peritonitis. Emergency laparotomy revealed extensive necrosis of the colon and rectum, with perforation at the hepatic flexure of the colon. A total colectomy, rectal resection, and ileostomy were performed. Postoperative pathology revealed acute and chronic suppurative inflammation with necrosis and perforation. Postoperative sepsis developed, and further examination revealed the presence of syphilis antibodies and liver function impairment. Following treatment with anti-infective, anti-inflammatory, liver-protective, and nutritional support therapies, the patient's condition improved. On the 9th postoperative day, the patient was transferred to a community hospital for further treatment and was discharged on the 23rd postoperative day. Conclusion: This case illustrates the rare occurrence of extensive necrosis and perforation of the colon in an HIV-infected patient with co-occurring syphilis. Although the precise role of syphilis in the development of gastrointestinal complications remains uncertain, this case highlights the need for heightened clinical awareness of co-infections in immunocompromised patients.