Toxic megacolon
Updates to Article Attributes
Toxic megacolon (TM) is a complication that can be seen in both types of inflammatory bowel disease, and less commonly in infectious colitis, as well as in some other types of colitis.
Pathology
The mechanisms involved in the development of toxic megacolon are not entirely clear, although chemical mediators such as nitric oxide and interleukins are thought to play a pivotal role in its pathogenesis 5.
Radiographic features
The colon (typically transverse colon) becomes dilated to at least 6 cm (usually greater). There is an additional loss of haustral markings, with pseudopolyps often extending into the lumen. Thumbprinting from mucosal oedema may be present. There may be signs of pneumoperitoneum if dilatation has progressed to cause perforation.
Practical points
- barium studies and colonoscopy should be avoided, due to the risk of perforation
-<p><strong>Toxic megacolon (TM)</strong> is a complication that can be seen in both types of <a href="/articles/inflammatory-bowel-disease">inflammatory bowel disease</a>, and less commonly in <a href="/articles/infectious-colitis">infectious colitis</a>, as well as in some other types of <a href="/articles/colitis">colitis</a>.</p><h4>Pathology</h4><p>The mechanisms involved in the development of toxic megacolon are not entirely clear, although chemical mediators such as nitric oxide and interleukins are thought to play a pivotal role in its pathogenesis <sup>5</sup>.</p><h4>Radiographic features </h4><p>The <a href="/articles/large-intestine-1">colon</a> (typically <a href="/articles/transverse-colon">transverse colon</a>) becomes dilated to at least 6 cm (usually greater). There is an additional loss of <a href="/articles/haustral-markings">haustral markings</a>, with <a href="/articles/inflammatory-pseudopolyp">pseudopolyps</a> often extending into the lumen. <a href="/articles/thumbprinting">Thumbprinting</a> from mucosal oedema may be present. There may be signs of <a href="/articles/pneumoperitoneum">pneumoperitoneum </a>if dilatation has progressed to cause perforation.</p><h4>Practical points</h4><ul><li>barium studies and colonoscopy should be avoided, due to the risk of perforation</li></ul>- +<p><strong>Toxic megacolon</strong> is a complication that can be seen in both types of <a href="/articles/inflammatory-bowel-disease">inflammatory bowel disease</a>, and less commonly in <a href="/articles/infectious-colitis">infectious colitis</a>, as well as in some other types of <a href="/articles/colitis">colitis</a>.</p><h4>Pathology</h4><p>The mechanisms involved in the development of toxic megacolon are not entirely clear, although chemical mediators such as nitric oxide and interleukins are thought to play a pivotal role in its pathogenesis <sup>5</sup>.</p><h4>Radiographic features </h4><p>The <a href="/articles/large-intestine-1">colon</a> (typically <a href="/articles/transverse-colon">transverse colon</a>) becomes dilated to at least 6 cm (usually greater). There is an additional loss of <a href="/articles/haustral-markings">haustral markings</a>, with <a href="/articles/inflammatory-pseudopolyp">pseudopolyps</a> often extending into the lumen. <a href="/articles/thumbprinting">Thumbprinting</a> from mucosal oedema may be present. There may be signs of <a href="/articles/pneumoperitoneum">pneumoperitoneum </a>if dilatation has progressed to cause perforation.</p><h4>Practical points</h4><ul><li>barium studies and colonoscopy should be avoided, due to the risk of perforation</li></ul>