Transverse colonic volvulus (TCV) was first described by Kallio in 1932 [2] and still remains a very rare cause of intestinal obstruction [2]. Classically, TCV is said to occur twice as often in women as in men; in the second and third decades of life. Some authors have reported a peak during the seventh decade of life [3,5]. In a normal situation, the transverse colon has a short mesocolon and is fixed at both ends, thus being less prone to volvulus. However, in the presence of various factors, such as congenital (abnormal fixation of the mesentery, congenital malformations of midgut rotation); mechanical (previous surgery, adhesions) and physiological (chronic constipation, pregnancy, colitis), it can lead to closed loop obstruction, gangrene, or even perforation in neglected cases [2-6].

Only 3–5% of all cases of intestinal obstruction are caused by colonic volvulus [1]. The transverse colon is involved in 2 to 4% [2,3] compared to 43 to 80% and 15 to 43% for the sigmoid colon and cecum, respectively [3]. A male predominance is noted [2]. Its pathogenesis is not yet completely understood. The predisposing factors are congenital, physiological and mechanical [1,5]. The two congenital properties responsible for a volvulus are redundancy and non-fixation [4]. Physiological causes include a high-forage diet and distention of the large intestine secondary to chronic constipation. This constipation is associated with psychiatric or neurological diseases [2]. Mechanical causes include anterior volvulus of the transverse or sigmoid colon, distal colonic obstruction, adhesions, colonic malposition following previous surgery, right colon mobility, inflammatory strictures, and neoplasm [1,5]. Other factors have been reported such as Chilaiditis syndrome [5], Clostridium difficile pseudomembranous colitis [7] and impaired intestinal motility associated with pregnancy.

The diagnosis is rarely made preoperatively. Plain abdominal radiographs may show massive dilatation of the proximal colon with empty distal bowel and two air-fluid levels caused by double closed-loop obstruction (at the transverse colon and cecum). However, plain x-rays are not very sensitive and may not contribute to the diagnosis. In such cases, a barium enema study can aid in the diagnosis by showing the typical "bird's beak." [4,10] Computed tomography (CT scan) has the highest sensitivity and will help delineate closed-loop obstruction, marked dilatation of the proximal colon and collapse of the distal portion of the transverse/descending colon, as well as the twisting of the mesenteric vessels, all of which suggest TCV [3,11]. Although there are occasional reports of successful conservative management [8, 11] of TCV, surgery is usually necessary in the vast majority of cases. Depending on the condition of the colon, surgical options may vary from simple derotation (and colopexy) in patients with a viable colon, to resection (with or without primary anastomosis) in the presence of gangrene or perforation. Resection of the redundant transverse colon presents the least risk of recurrence.

Diagnosis of transverse colonic volvulus is difficult because it does not have the same classically recognizable radiographic features as sigmoid and cecal volvulus. It is generally performed intraoperatively. In the subacute type, early diagnosis by CT scan is recommended [6].

While the sigmoid volvulus can be decompressed by colonoscopy, the transverse colonic volvulus must be surgically untwisted urgently [5]. Resection is the treatment of choice to prevent recurrence [1,5]. In fact, detorsion alone or combined with colopexy has a higher recurrence rate than resection [1,5]. The incidence of recurrent volvulus after anterior resection and primary anastomosis varies between 22% and 36% [2]. Thus, some authors recommend considering a subtotal colectomy in the presence of a megacolon, rather than a partial resection of the involved intestinal segment [2]. This resection is carried out with or without primary anastomosis depending on the appearance of the colon, the existence or not of peritonitis and the patient's state of health. Our patient underwent a subtotal colectomy with ileo-sigmoidostomy.