International Journal of Academic Medicine

: 2017  |  Volume : 3  |  Issue : 1  |  Page : 194--196

Giant megacolon: An unusual surgical emergency

Thomas R Wojda1, Franz Yanagawa2, Alexander Wallner3, WT Hillman Terzian1, Ellyn A Smith1, Stanislaw P Stawicki1, James Cipolla1,  
1 Department of Surgery, St. Luke's University Health Network, Bethlehem, PA, USA
2 Temple University School of Medicine, St. Luke's University Hospital Campus, Bethlehem, PA, USA
3 Department of Surgery, Division of Acute and Adult Trauma Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA

Correspondence Address:
Stanislaw P Stawicki
Department of Surgery, St. Luke's University Health Network, 801 Ostrum Street, Bethlehem, PA 18015


Giant megacolon (GMC), an advanced form of chronic megacolon, is an uncommon diagnosis that may evolve into a surgical emergency. Here, we demonstrate a case of an elderly male who presented to our hospital with complaints of acute abdominal distention and diffuse abdominal pain. He was emergently taken to the operating room where necrotic cecum was found. The patient underwent total abdominal colectomy with end ileostomy. Radiographic and operative images of GMC are presented. The authors also discuss the pathophysiology and clinical management of this surgical condition. The following core competencies are addressed in this article: Medical knowledge, Patient care.

How to cite this article:
Wojda TR, Yanagawa F, Wallner A, Hillman Terzian W T, Smith EA, Stawicki SP, Cipolla J. Giant megacolon: An unusual surgical emergency.Int J Acad Med 2017;3:194-196

How to cite this URL:
Wojda TR, Yanagawa F, Wallner A, Hillman Terzian W T, Smith EA, Stawicki SP, Cipolla J. Giant megacolon: An unusual surgical emergency. Int J Acad Med [serial online] 2017 [cited 2022 Oct 2 ];3:194-196
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Megacolon can be defined as colonic dilatation >6.0 cm in one or more colonic segments.[1],[2] Some authors have suggested that measured diameter of >6.5 cm at the transverse and rectosigmoid locations,[3] >8 cm for the ascending colon,[4],[5] and >12 for the cecum [4],[5] may provide a more precise categorization.[3],[4],[5],[6] Megacolon can present either acutely or as a chronic condition.[7] This heterogeneous entity can be broadly grouped into Hirschsprung's (e.g., congenital)[8],[9] or non-Hirschsprung's (e.g., acquired)[3],[10],[11] megacolon types. The latter form is the focus of the current report.

The genesis of chronic megacolon is poorly understood and involves pathologic changes in the intestinal connective tissue, smooth muscle cells, and the enteric nervous system.[10],[12],[13] Clinical hallmarks of chronic megacolon include abdominal pain, bloating, and constipation.[10] Among chronically institutionalized patients, megacolon can progress to “giant megacolon” (GMC), often accompanied by the clinical picture of “large-bowel obstruction with obstipation.”[14] Herein, we describe a case of GMC with acute presentation requiring the performance of emergency total abdominal colectomy with end ileostomy.

 Clinical Vignette

A 76-year-old male presented from a nursing home with progressive abdominal distention. Due to cognitive decline, the patient was only able to provide a limited history of “abdominal pain.” His medical record indicated that he suffered from progressive dementia, hypertensive, and an insulin-dependent diabetic. On physical examination, he was tachycardic at 114 beats/min, tachypneic at 24 breaths/min, and hypotensive with blood pressure of 78/53 mmHg. His abdomen was severely distended, with diffuse tenderness to palpation. The patient's laboratory results were significant for leukocytosis of 14,500 cells/μL, hypokalemia at 3.3 mmol/dL, and hypomagnesemia of 1.2 mmol/dL. Abdominal radiograph demonstrated massively dilated large bowel [Figure 1].{Figure 1}

Given the patient's acute clinical presentation, signs of systemic inflammatory response, and the presence of peritonitis on examination, he was taken urgently to the operating room. Upon entering the peritoneum, the patient was found to have a necrotic and friable cecum. A subtotal colectomy was performed [Figure 2] for photograph of surgical specimen, and end ileostomy was created. The patient subsequently spent 3 days in the intensive care, followed by an additional week in the hospital. He eventually recovered sufficiently to allow discharge back to the nursing home.{Figure 2}


Chronic megacolon is a progressive condition that can present acutely in its terminal stages.[7] This heterogeneous entity can be broadly categorized either as Hirschsprung's disease that primarily affects pediatric patients [8],[9] or adult-onset, non-Hirschsprung's megacolon.[3],[10] Of note, the latter idiopathic entity is distinct from Ogilvie's syndrome or acute colonic pseudo-obstruction.[15] Among institutionalized patients, chronic megacolon can progress to so-called GMC, characterized by the presence of obstipation and large-bowel obstruction.[14]

The pathophysiology of chronic megacolon is poorly understood and involves progressive changes within the intestinal connective tissue, smooth muscle cells, and the associated enteric/extrinsic nerves.[10],[12] Various neurological, metabolic, endocrine, connective tissue, and muscle disorders have been associated with the appearance of megacolon.[16],[17] Certain pharmacologic therapies (e.g., tricyclic antidepressants, phenothiazines, and clonidine) may also be contributory.[16] Idiopathic slow-transit constipation, likely a result of several of the above factors presents simultaneously, is hypothesized to lead to the development of chronic megacolon.[18],[19] Mechanistically, chronic megacolon is associated with the loss of enteric neuronal function with submucosal connective tissue and smooth muscle destruction. In a histopathologic study of patients with idiopathic megacolon, it was found that approximately 36% had myopathy, 61% had neuropathy, and 32% had mesenchymyopathy.[20] GMC is thought to represent the end-stage manifestation of chronic megacolon.[21]

Clinical hallmarks of chronic megacolon include abdominal pain (84% patients), bloating, and abdominal distention (95% cases).[10] Chronic constipation combined with the evidence of decreased gastrointestinal motility is important components of associated medical history, with an average of 1.5 bowel movements per week in affected patients.[10] When evaluating chronically institutionalized patients presenting with abdominal distention, it is important to consider other serious colonic disorders such as toxic megacolon, Ogilvie's syndrome, and various forms of mechanical obstruction.[22],[23] As exemplified by the current case scenario, chronic megacolon can evolve into a surgical emergency, with associated life-threatening tissue ischemia and/or colonic perforation.[24] Obtaining detailed history of the disease is important, including past treatments and a complete list of medications.

Cases of chronic megacolon are initially treated conservatively, with a combination of laxatives, enemas, and avoidance of constipating medications. Optimized management of any underlying medical condition is critical. For refractory nonemergent cases, surgery is generally well tolerated, with the most commonly performed operation being total abdominal colectomy with ileorectal anastomosis. Success rates after subtotal colectomy, defined as improvement in symptoms and at least 1–2 bowel movements per day, are in excess of 80%.[25]


The current case demonstrates the end-stage presentation of chronic megacolon – a serious, progressive condition that continues to be poorly understood. The patient described herein presented acutely with massively and diffusely dilated colon, also known as “GMC.” Due to hemodynamic instability and cecal necrosis, the patient underwent emergent total abdominal colectomy with end ileostomy. An overview of pathophysiologic and clinical management considerations pertinent to GMC is also provided.

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