Splenic flexure intussusception: a rare complication post colonoscopy

Intestinal intussusception occurs when a segment of bowel invaginates into the adjacent distal intestine, which can result in complications such as bowel obstruction and ischaemia. It is rare in adults and only accounts for 5% of cases that present as small bowel obstruction and in almost 90% of these cases a lead point can be identified. Typical precipitating causes of intussusception in adults include small intestinal polyps, benign tumours (including leiomyomas and neurofibromas), malignant tumours, inflammatory bowel disease, postoperative adhesions, Meckel’s diverticulum and feeding tubes. Intussusception following a colonoscopy is even more rare. There are only 10 cases reported in the literature with the first being reported in Japan in 2000. To our knowledge, there has been only one case reported in Australia, where a patient presented with an ascending colon to hepatic flexure intussusception. This spontaneously resolved and subsequent repeat colonoscopy demonstrated submucosal nodular swelling which was biopsy-proven colitis. A previously well 36-year-old lady presented with intermittent colicky abdominal pain, nausea and vomiting with loose non-bloody stools. This was on a background of a diagnostic gastroscopy and colonoscopy the day prior for investigation of chronic abdominal pain for the preceding 12 months. The colonoscopy demonstrated rightsided diverticular disease and small haemorrhoids only. There were no transverse or left colon pathologies. She was haemodynamically stable with global tenderness without distension, guarding or peritonism. Her blood investigations showed a haemoglobin of 147 g/L, white cell count of 11.1 10/L, C-reactive protein of 5.9 mg/L and venous blood gas lactate of 1.3 mmol/L. Erect chest radiograph was done and demonstrated no subdiaphragmatic free air to indicate perforation. Subsequent computed tomography (CT) of the abdomen and pelvis was done which was suggestive of colo-colic intussusception involving distal transverse colon and splenic flexure (Fig. 1). She was admitted to hospital and commenced on intravenous fluids, empirical antibiotics (ceftriaxone and metronidazole), antiemetics and analgesia. Shortly thereafter, she underwent diagnostic laparoscopy due to worsening pain and tachycardia, which revealed a distal transverse colo-colic intussusception, consistent with CT findings, with a small amount of reactive peritoneal fluid as well as inflammatory exudates with congestion (Fig. 2). The intussusception was reduced and an ontable post-reduction colonoscopy was done. This revealed a viable bowel with some venous congestion and mucosal oedema (Fig. 3). The patient had an uneventful recovery and was soon discharged. Follow-up in the clinic and repeat CT found no new abnormalities. Intussusception following colonoscopy is a rare occurrence. In all the previous cases that have been reported, it was almost exclusively in the right colon. Our case demonstrated intussusception near the distal transverse colon and splenic flexure which is unique. The aetiology is suspected to be secondary to mucosal oedema which may have been caused during the initial colonoscopy by either manoeuvring of the colonoscope or excessive suctioning. Other case reports noted in the literature suggest that sites of biopsies or polypectomy could act as lead points and previous surgeries involving the large bowel can predispose to cause intussusception. In these cases, non-operative management was successful in two patients with spontaneous resolution, while the rest required either laparotomy or laparoscopy with or without colonoscopy. Only one was managed with colonoscopy alone. Five patients underwent bowel resection, none of which hadmalignant pathology. The early access to diagnostic imaging at emergency departments and increase in the number of colonoscopies performed every year might