Complex ileo‐caeco‐sigmoid fistula: a rare cause of small bowel obstruction

Abstract

A 67-year-old lady presented with abdominal pain, bilious vomiting, abdominal distension, constipation and obstipation for 3 days. She also had respiratory distress for 1 day. She is a known case of bronchitis on medications for 5 years. She underwent hysterectomy and cholecystectomy 30 and 7 years back, respectively. On clinical examination, the patient was tachypnoeic and haemodynamically stable with abdominal distension and hyperperistaltic bowel sounds. Blood investigations showed leucocytosis, dyselectrolytemia and deranged renal function tests. Abdominal radiograph revealed dilated small bowel loops with air fluid levels (Fig. 1a). Noncontrast computed tomography (CT) of the abdomen revealed dilated proximal small bowel loops with bird-beak narrowing at the level of terminal ileum suggestive of stricture (Fig. 1b). The large bowel loops were collapsed. High-resolution CT chest showed endarterial nodular lesions having ‘tree-in-bud’ appearance involving both lungs with multiple enlarged mediastinal lymph nodes suggestive of pulmonary tuberculosis (Fig. 1c). A provisional diagnosis of small bowel obstruction secondary to adhesions or tuberculosis was made. After obtaining informed written consent, the patient was planned for exploratory laparotomy. On laparotomy, there was no ascites, peritoneal or omental deposits or tubercles. Small bowel loops were grossly dilated up to the terminal ileum. Complex ileo-sigmoid and caeco-sigmoid internal fistulae very close to each other leading to dense adhesions and small bowel obstruction were present (Fig. 2). The fistulae were dismantled with primary closure of the caecal and sigmoid openings. The involved part of the terminal ileum was resected and ileostomy was constructed. No tumor or diverticulum was identified at the fistula site. The operative time was 120 min with blood loss of 100 mL. Post-operatively, the patient requires invasive ventilation for 2 days followed by non-invasive ventilation for 15 days with total hospital stay of 26 days. Patient was started on antitubercular treatment in the post-operative period along with other supportive medications. Histopathology of the ileal, caecal and sigmoid biopsy showed non-specific inflammation with no evidence of granuloma or malignancy. Currently, at 4 months of follow-up, the patient is doing well without any symptoms and planned for stoma closure. Gastrointestinal (GI) fistulas are complex clinical conditions associated with significant morbidity and mortality. The GI fistulas can be internal or external. Most of the external fistulas are seen in the post-operative period after abdominal surgeries. The common causes of internal GI fistulas include Crohn’s disease (CD), cancer, diverticulitis, iatrogenic injuries and trauma. The most common sites for internal GI fistulas are ileosigmoid, caecosigmoid, ileoileal and ileojejunal. Rarely, primary GI fistula that communicate with the other organs have also been described. However, a complex ileo-caeco-sigmoid fistula seen in the present case has not been described in the English literature. The clinical symptoms in internal GI fistula depend upon the location and cause of the fistula. The most common symptoms include altered bowel habits, abdominal pain and blood or mucus in stools. Non-GI organ symptoms such as cough, fever and skin lesions in cases of systemic diseases such as tuberculosis or CD