Investigations; 1- Sigmoidoscopy should be performed in all cases where blood & mucous have been passed.

2- Colonoscopy, either short (60 cm) flexible colonoscopyis done which need minimal bowel preparation (by immediate disposable enema) or by using total colonoscopy which need complete bowel preparation & has the advantage of picking up the primary carcinoma & the synchronous lesions of the colon if present.

3- Radiography, barium enema shows a constant, irregular filling defect but negative X-ray finding will not exclude small carcinoma of the colon in patients with high suspicion of the disease.

CT examination: Contrast enhanced axial scans: An intraluminal, bulging soft tissue mass is visible in the ventral wall of the ascending colon (upper pictures-arrows). Distally the lumen is narrowed, the circular thickening of the mucosal wall is irregular, the adjacent fat is infiltrated (lower pictures - arrows (

Colonography: An 'apple-core' lesion of the colon is visible as a well- demarcated, circular, 1.5 cm long, irregular narrowing (arrow).

Barium enema: A 6 cm long section of the recto-sigmoid region has irregular contour, narrowed lumen (1 cm) and filling defect (arrow).

Enterography: Multiple narrowing of the terminal ileum is visible (arrow). The tumor involves the cecum and the ascending colon (double arrow).

4- Exfoliative cytology, is of valuable help in diagnosis of carcinoma colon cases when endoscopy is not available, & this need good & careful bowel preparation, here after 5-10 min. the returned fluid is collected & centrifuged & the sediment is prepared & stained & examined.

Treatment: Preoperative preparation; I- when there is no intestinal obstruction, 1.The patient should receive blood to correct the anemia. 2.Mechanical preparation to cleans the bowel by using;

1.Strong purgatives. 2.Whole bowel irrigation. 3.Enemas or combination of the above

3- High caloric & low residue diet. 4- Chemical preparation, by using metronidazole (flagyl) to deal with anaerobic microorganisms in conjunction with gentamycin or by using third generation cephalosporins.

II- When there is intestinal obstruction a preliminary drainage of the intestine proximal to the obstruction must be performed especially in cases of Lt. Side colonic cancer. In cases of Rt. Side lesions a primary resection + end to end ileo-colic anastomosis is done.

Tests of operability; at opening the peritoneal cavity the operability should be seen at first by; 1.Palpating the liver for secondary metastasis. 2.Neoplastic implantation in the peritoneum especially the pelvic peritoneum.

3- Variant groups of lymph nodes that drains the involved segment, although their enlargement will not necessarily mean neoplastic invasion. 4- Fixity of the tumor to the underlying structures.

The operations to be described are designated to remove both the primary lesion as well as the loco-regional lymph nodes.

Types of operations; 1.Rt. Hemicolectomy treats carcinoma of the cecum or the ascending colon. 2.Carcinoma of the hepatic flexure, the resection here is extended Rt. Hemcolectomy to involve the transverse colon & splenic flexure also.

3- Carcinoma of transverse colon, by excision of transverse colon + both flexures together with greater omentum is the operation of choice. 4- Carcinoma of the splenic flexure or descending colon is treated by removing the transverse colon & the segment involved by tumor. 5- Carcinoma of pelvic colon, treated by Lt. Hemicolectomy.

With each type of the above operation the continuity of the bowel is restored by end to end anastomosis + putting drain down to the site of anastomosis.

Post-operative care includes; 1.Administration of antibiotics. 2.Free fluids are not given by mouth after anastomosis until flatus is passed.

In cases of inoperable carcinoma of the colon, a proximal colostomy is done in case of tumor of pelvic or descending colon, while ileo-transverse Anastomosis is done to by pass the obstructive tumor in case of carcinoma of ascending colon or the cecum.