Colon stenosis

Obstruction of the esophagus, stomach, small intestine, and colon has occurred when bulk-forming laxatives are administered without adequate fluid intake or in patients with intestinal stenosis. 

A single case report described a self-administered ammonium solution enema that resulted in anal pain, diffuse abdominal colic, and tenesmus (da Fonseca et al. 1998). Sigmoidoscopy showed diffuse erythematous friable mucosa with large ulcerations covered by yellowish exudate. Six days later, the ulcers had receded, but the colon was still erythematous. Three months postexposure, biopsies showed chronic inflammation and fibrosis of the rectum and sigmoid colon, but no stenosis. 

Complete absence ofthe colon andrectumisextremely rare. However, segmental atresias or stenosis of the colon are seen more often and are believed to be secondary to an intrauterine vascular insult. Nevertheless they are still quite unusual and are seen much less commonly than atresias in the small bowel. The colon typically accounts for only 5%-15% of total... 

Fig. 6.11a,b. Colonic atresia and stenosis, a Colonic atresia in a neonate with a small distal colon and a blind upper end. b Colonic atresia showing a lower bowel well distended with contrast but with no connection to the more proximal bowel... 

Rare complications as have been reported in literature are aortic and bronchial necrosis [58], bronchial stenosis [59], unilateral diaphragmatic paralysis [60], pulmonary infarction (especially in patients who have suffered pulmonary artery embolism), left main bronchial-esophageal fistula [61], and non-target embolization (colon, coronary and cerebral circulation) [62]. Especially the newer spherical embolic materials (tris-acryl gelatin) can traverse from the bronchial into the pulmonary circulation, and then through unoccluded pulmonary arteriovenous malformations into the systemic circulation [41]. 

Fig. 17.16 Sigmoid diverticulitis. Multiple air-containing diverticula are found along the sigmoid colon. In this patient with acute pelvic pain, focal wall thickening, stenosis, and paracolic fat stranding (arrow) are signs of acute diverticulitis involving the distal sigmoid colon. R, rectum...

Deans GT, Krukowski ZH, Irwing St (1994) Malignant obstruction in the left colon. Br J Surg 81 1270-6 De Baere T, Harry G, Ducreux M, Elias D, Briquet R, Kuoch V, Roche A (1997) Self-expanding metallic stents as palliative treatment of malignant gastro-duodenal stenosis. AJR 169 1079-1083... 

Rodier B, Espinoza P, Foissy P (1987) Segmental tuberculosis of the colon manifested by rectal stenosis. Ann Gastroenterol Hepatol 23 347-349... 

Within the group of inflammatory howel diseases (IBD), Crohn s disease (CD) and ulcerative colitis (UC) represent the most important conditions. CT colonog-raphy helps to assess the colon proximal to a stenosis, which cannot be passed with endoscopy (Ota et al. 2003) (Table 13.2). Furthermore, CT colonography is useful for evaluating the extracolonic extent and complications of the disease. The i.v. administration of contrast is helpful for the evaluation of inflammatory wall changes (Harvey et al. 2001). 

The risk of development of colorectal cancer increases with the extent and the duration of the disease, Focal wall thickening, shoulder formation, or large polypoid lesions are suspicious for the development of colorectal cancer (Fig. 13.9. a-c). Differentiation between an inflammatory stenosis in ulcerative colitis and cancer is the domain of endoscopy with biopsy, but CTC maybe used as an adjunct in patients with an endoscopically non-assessable colon. 

Fig. 13.10a-c. Crohn s disease Skip lesions (arrow) in the terminal ileum and the transverse colon (a,b). Irregular wall thickening and stenosis of the transverse colon with pericolic fat stranding and flattening and disappearance of the haustra (arrow) (b). Virtual colonoscopy shows luminal narrowing and cobblestone pattern... 

Fig. 13.11. a Crohn s disease stenosis in the transverse colon (arrow), b Ileo-cecal fistula (arrow) and stenosis in the ascending colon, c Conglomerate mass between cecum and small bowel loops (arrow)... 

The most common pitfalls are inflammatory stenosis and the segmental colonic spasm. Inflammatory and post-inflammatory stenosis more often show cone-shapedmildwall thickening with involvement of a long segment (>10 cm) and pericolonic fat stranding. Sometimes fluid is present at the root of the mesentery (Chintapalli et al. 1999) (compare Figs. 13.10b and 13.11a, vs Fig. 13.14 and 13.15). 

Fig. 13.16a-d. Segmental colonic spasm in the descending colon (arrow) focal, irregular circular wall thickening with shoulder formation in the supine position (a-c). The lesion shows soft tissue attenuation and CM enhancement (a). Normal colon wall without wall thickening or stenosis in the prone position (d). It is important to identify the same segment as in the supine position... 

The radiologic patterns of primary colonic lymphoma, such as intraluminal masses, polyps, stenosis, and polyposis, are often quite similar to those of carcinomatous stenosis, adenomatous polyps, and familial polyposis, and can also be evaluated by CT colonography (Table 13.4). The possibility of lymphoma should be considered when cecal tumors involve the terminal ileum, when tumors do not invade the pericolonic fat or adjacent structures and when there are secondary findings such as splenomegaly or bulky abdominal lymph node enlarge-... 

Follow-up of the location and the lumen of a stent may be feasible with CT colonography. Particularly if endoscopy is incomplete or if stents could not be passed by conventional colonoscopy, CT colonography could be an alternative for contrast enema. CT colonography provides additional information about the location and the lumen of the stent and the proximal colon (Fig. 13.20a-c). In case of re-obstruc-tion because of tumor recurrence, the additional 2D displays demonstrate the morphology of the stent-stenosis, which might be helpful for further treatment. During the same procedure, the extracolonic conditions of the disease (metastases, lymph nodes) can be evaluated. 

Fig. 13.19a,b. Inflammatory stenosis at the anastomosis after colonic resection Mild wall thickening with stenosis and pericolic fat stranding arrow). Virtual colonoscopy shows luminal narrowing (arrow) and a diverticula... 

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