Obstruction colonic

Obstructing disorders Pyloric obstruction Small bowel obstruction Colonic obstruction Achalasia... 

CTC in symptomatic patients is to be considered when colonoscopy can not be completed or carried out this may occur due to mechanical hindrance such as pelvic adhesions, in cases of high risk of perforation as in complicated diverticular disease, when there is an obstruction due to cancer or extracolonic diseases, when the cecum cannot be reached in extreme dolicocolon conditions, or in patients with poor tolerance to colonoscopy in whom heavy sedation may be dangerous (elderly patients or patients with severe co-morbidity). Such indications are similar to those of double contrast barium enema (DCBE) however, CTC has been shown to be both more accurate and better tolerated than DCBE, and should be used preferentially whenever available (Rocket et al. 2005 Taylor et al. 2005 Taylor et al. 2006). Furthermore, in cases of obstructing colonic cancer, CTC is a valuable tool, as it can be conveniently performed at the time of a contrast-enhanced abdominal CT scan for staging purposes to detect synchronous colorectal carcinomas, metas-... 

Contraindication to sedation Obstructing colon mass Post-operative colorectal cancer surveillance High risk patients Scanner weight limitations Pregnancy Hip joint replacement Incompetent ileocecal valve Claustrophobia ... 

The assessment of colon proximal to an obstructing colonic mass has been a shortcoming of conventional colonoscopy. In the past, inter-operative palpation or post-operative colonoscopy was performed with the possibility of a second surgery required for a missed synchronous cancer or adenoma. The sensitivity of hand palpation is fairly low and intraoperative insufflation of the colon increases the risk of peritoneal contamination. 

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. 

The a-glucosidase inhibitors are contraindicated in patients with a hypersensitivity to the drug, diabetic ketoacidosis, cirrhosis, inflammatory bowel disease, colonic ulceration, partial intestinal obstruction or predisposition to intestinal obstruction, or chronic intestinal diseases. Acarbose and miglitol are used cautiously in patients with renal impairment or pre-existing gastrointestinal (GI) problems such as irritable... 

Pulmonary disease is characterized by thick mucus secretions, impaired mucus clearance, chronic airway infection and colonization, obstruction, and an exaggerated neutrophil-dominated inflammatory response. 

Endoscopic approaches are typically used and may include colonoscopy, proctosigmoidoscopy, or possibly upper GI endoscopy in patients with suspected CD. Endoscopy is useful for determining the disease distribution, pattern and depth of inflammation, and to obtain mucosal biopsy specimens. Supplemental information from imaging procedures, such as computed tomography (CT), abdominal x-ray, abdominal ultrasound, or intestinal barium studies may provide evidence of complications such as obstruction, abscess, perforation, or colonic dilation.3... 

Imaging Abdominal x-ray (-) obstruction, perforation, or colonic dilation... 

Flexible sigmoidoscopy can be performed to identify obstruction in the rectum and lower colon, whereas colonoscopy can evaluate the entire colon for organic disease. 

Toxic megacolon Suggested by acute dilatation of the colon to a diameter greater than 6 cm, associated systemic toxicity, and the absence of mechanical obstruction. It carries a high mortality rate. 

The clinical conditions that most often necessitate emergency colonic operations are acute hemorrhage, perforation, ischemia, obstruction and trauma. In these circumstances, the operation must be performed without any bowel preparation because oral antibiotic prophylaxis and mechanical cleansing are either impossible or potentially harmful. 

Table 4. Antimicrobial and mechanical bowel preparation in patients with obstructing intestinal lesions or undergoing emergency colonic surgery... 

In a small percentage of patients presenting with complaints of constipation, surgical procedures (such as intestinal resection) are necessary. Surgery is usually necessary with most colonic malignancies and with GI obstruction from a number of causes. 

Coverage against obligate anaerobic bacilli should be provided for distal small-bowel and colon-derived infections and for more-proximal gastrointestinal perforations when obstruction is present. 

Common complications of surgery for both colon and rectal cancer include infection, anastomotic leakage, obstruction, adhesions, and malabsorption syndromes. 

There are two different mechanisms behind ordinary causes of constipation, functional and outlet obstructions. Functional constipation is caused by the slower movement of the colon, peristalsis, which comes with old age, often in combination with less physical activity and less intake of fibre containing food. Outlet obstruction is a result of incapacity to empty the rectum from faeces often due to too large masses of stool blocking the anus. It can also be caused by anal stricture from haemorrhoids or scar tissue caused by fissures. 

Diabetic ketoacidoses inflammatory bowel disease colonic ulceration partial intestinal obstruction patients predisposed to intestinal obstruction chronic intestinal diseases associated with marked disorders of digestion or absorption or with conditions that may deteriorate as a result of increased gas formation in the intestine hypersensitivity to the drug or any of its components. 

Constipation Serious complications of constipation, including obstruction, perforation, impaction, toxic megacolon, secondary colonic ischemia, and death have been reported with use of alosetron. Immediately discontinue alosetron treatment in patients who develop constipation. 

Approximately 1 to 1.5 L of fluid is ingested per day, and coupled with secretions from the stomach, pancreas, and proximal duodenum, approximately 8 L of chyme enters the jejunum per day. Reabsorption of 6 to 7 L occurs within the small bowel, leaving a residual of 1.5 L fluid, 90% of which is reabsorbed in the colon. This pattern of liquid reabsorption permits the elimination of fecal waste containing an average of 0.1 to 0.2 L fluid per day. Diarrhea occurs if there is an altered rate of intestinal motility, if mucosal function or permeability is altered, or if the fluid load entering the colon overwhelms colonic reabsorption. Constipation may occur if intestinal movement is inhibited or if there is a fixed obstruction. 

Laxatives are used to increase stool frequency and reduce stool viscosity. Even with long-term use, bulk laxatives and pure osmolar laxatives do not predispose patients to formation of a cathartic-type colon and should be the initial agents used for chronic constipation after a structural obstructing lesion has been excluded. Laxatives are also used before radiological, endoscopic, and abdominal surgical procedures such preparations quickly empty the colon of fecal material. Nonabsorbable hyperosmolar solutions or saline laxatives are used for this purpose. Classification and comparison of representative laxatives are provided in Table 40.1. 

Castor oil is a bland oil that is hydrolyzed in the gut to yield ricinoleic acid, the active purging agent. This hydrolysis requires bile, a fact that is sometimes overlooked when castor oil is given as a laxative before radiography in biliary obstruction. The ricinoleic acid acts on the ileum and colon to induce an increased fluid secretion and colonic contraction. 

Cholinomimetics Neostigmine often used for colonic pseudo-obstruction in hospitalized patients... 

Whether administered in combination or as a single therapy for cancers of the head, neck and colon, cetuximab exhibits similar pharmacokinetic characteristics. After a 2-h infusion of 400 mg/m2, the half-life is 97 h, ranging from 41 to 213 h, and after initial and subsequent maintenance doses, the half-life is about 112 h, ranging from 63 to 230 h. The adverse effects associated with cetuximab include immuno-genicity, electrolyte depletion (hypomagnesemia) and infusion reactions. Infusion reactions involve airway obstruction, urticaria and hypotension. 

A small child died when impacted resin obstructed the colon (SEDA-8, 935 8). 

In the patient presenting with a recent onset of constipation, an obstructing lesion of the colon should be sought. In addition to a colonic neoplasm, other causes of colonic obstruction include strictures due to colonic ischemia, diverticular disease, or inflammatory bowel disease foreign bodies or anal strictures. Anal sphincter spasm due to painful hemorrhoids or fissures also may inhibit the desire to evacuate. 

Fig. 14.1. (A) Implantation of HT-29LP tumor cells into the posterior wall of the rectum. The anterior wall of the anorectal area is cut 7 mm in length between two hemostats to prevent colonic obstruction, resulting from tumor progression. Tumor cells are then injected submucosally using a 27 G needle. (B) At the end of the study period, the abdominal cavity is exposed through a midline incision and para-aortic lymph nodes (arrow), located around the abdominal aorta, are removed and imaged ex vivo.

The anorectal wall is cut 7 mm in length between the two hemostats to prevent colonic obstruction, resulting from rectal tumor progression (Fig. 14.1 A). 

Abdominal pain and discomfort This is frequently non-specific and may present as a vague, dull pain. Persistent and colicky pain is most likely to represent obstructive symptoms and be caused by a lesion in the descending colon. 

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