Benign Colorectal conditions

1. Benign Colorectal conditions Manal Mubarak AlQuaimi KFMC R1 GS

2. Objectives

3. Anatomy + embryology • 3rd week , primitive gut tube , then it devided into 3 regions : midgut which open ventrally , foregut and hindgut , • Note • Pictures

4. Physiology • Colon Function : س • Absorption : • Electrolytes transport • Nutrition

5. Physiology • Motility pattern in colon : • Retrograde • Segmental • Mass movement • + Colonic gas • Microflora

6. Classification • Disorder of physiology : or obstruction ?? • Constipation • Volvulus • Colonic obstruction • Diverticular diseases • Acuired vascular abnormalities and lower GI bleeding • Colitis “ types “ \ • Infectious colitis • Colonic ischemia • Inflamatory ??

7. Constipation • Constipation is generally defined clinically as one or fewer spontaneous bowel movements or stools per week, though patients may use the term to describe a number of different defecatory symptoms.

8. Etiologies: • medications (narcotics, anticholinergics, antidepressants, calcium channel blockers), • hypothyroidism, hypercalcemia, • dietary factors (low fluid or fiber intake), • decreased exercise, • neoplasia, • neurologic disorders (e.g., Parkinson disease and multiple sclerosis). • Abnormalities of pelvic floor function (obstructed defecation), such as paradoxical puborectalis muscle function or intussusception of the rectum (internal or external rectal prolapse), • idiopathic delayed transit of feces through the colon (dysfunction of the intrinsic colonic nerves or colonic inertia).

9. Evaluation.??xrayChange in bowel habits is a common presentation of colorectal neoplasia. The initial evaluation of constipation should include digital rectal exam and colonoscopy. If this workup is negative and the patient fails to respond to a trial of fiber supplementation and increased fluid intake, the next step is a colonic transit time study. The patient is given a standard amount of fiber (12 g of psyllium per day) for a week prior to the test and continued throughout the study. On day 0, the patient ingests an enteric-coated capsule containing 24 radiopaque rings. Abdominal plain X-rays are obtained on days 3 and 5. Normal transit results in 80% of the rings in the left colon by day 3 and 80% of all the rings expelled by day 5. The persistence of rings throughout the colon on day 5 indicates colonic inertia. When the rings stall in the rectosigmoid region, functional anorectal obstruction (obstructed defecation) may be present. This may be evaluated with cine defecography, anorectalmanometry, or both; the task is to look for nonrelaxation of the puborectalis muscle or internal intussusception of the rectum.

10. Treatment of colonic inertia initially includes increased water intake, laxatives (polyethylene glycol, 12 oz/day), fiber (psyllium 12 g/day), increased exercise, and avoidance of predisposing factors. In patients with long-standing, debilitating symptoms refractory to nonoperative measures, total abdominal colectomy with ileorectal anastomosis may prove curative. The risk of total intestinal inertia after surgery is significant, and the patient should understand this.

11. Volvulus • Volvulus is the twisting of an air-filled segment of bowel about its mesentery and accounts for nearly 10% of bowel obstruction in the United States. • Sigmoid volvulus accounts for 80% to 90% of all volvulus and is most common in elderly and in patients with a variety of neurologic disorders. It is an acquired condition resulting from sigmoid redundancy with narrowing of the mesenteric pedicle. • Diagnosis is suspected when there is abdominal pain, distention, cramping, and obstipation. Plain films often show a characteristic inverted-U, sausage-like shape of air-filled sigmoid pointing to the right upper quadrant. If the diagnosis is still in question and gangrene is not suspected, water-soluble contrast enema usually shows a bird's-beak deformity at the obstructed rectosigmoid junction.

14. Volvulus • In the absence of peritoneal signs, treatment involves sigmoidoscopy, with the placement of a rectal tube beyond the point of obstruction. The recurrence rate after decompressivesigmoidoscopy approaches 40%; therefore, elective sigmoid colectomy should be performed in acceptable operative candidates. If peritonitis is present, the patient should undergo laparotomy and Hartmann procedure (sigmoid colectomy, end-descending colostomy, and defunctionalized rectal pouch). An alternative in the stable patient without significant fecal soilage of the peritoneal cavity is sigmoidectomy, on-table colonic lavage, and colorectal anastomosis with or without proximal fecal diversion (loop ileostomy).

15. Volvulus • Cecal volvulus • younger population than does sigmoid volvulus, likely due to congenital failure of retroperitonealization of the cecum (in axial volvulus) or a very redundant pelvic cecum that flops into the left upper quadrant to kink the right colon (in bascule volvulus). • Diagnosis. Presentation is similar to that of distal small-bowel obstruction, with nausea, vomiting, abdominal pain, and distention. Plain films show a coffee bean-shaped, air-filled cecum with the convex aspect extending into the left upper quadrant. A Hypaque enema may be performed, which shows a tapered (in axial volvulus) or linear cutoff (in bascule volvulus) of the ascending colon.

16. Volvulus • Managementinvolves urgent laparotomy and right hemicolectomy. Cecopexy has an unacceptably high rate of recurrent volvulus, and although cecectomy will prevent recurrence, it is technically more challenging than formal right hemicolectomy. Colonoscopic decompression is not an option.

17. Volvulus • Transverse volvulus is rare and has a clinical presentation similar to that of sigmoid volvulus. Diagnosis is made based on the results of plain films (which show a dilated right colon and an upright, U-shaped, dilated transverse colon) and contrast enema or computed tomography (CT). Endoscopic decompression has been reported, but operative resection is usually required

18. Colonic obstruction • Dynamic ( mechanical ) Vs. Adynamic ( pseudo ) • Mechanical obstruction : Blockage (luminal, mural, or extramural)  intestinal contractility as a physiologic response to relieve the obstruction • Pseudo-obstruction is characterized by the absence of intestinal contractility, often associated with decreased or absent motility of the small bowel and stomach.

19. Colonic obstruction • Colorectal cancer , colonic • Intraluminal : fecal impaction, inspissated barium, and foreign bodies. • Intramural causes: carcinoma, include inflammation (diverticulitis, Crohn's disease, lymphogranulomavenereum, tuberculosis, and schistosomiasis), Hirschsprung'sdisease, ischemia, radiation, intussusception, and anastomotic stricture. • Extraluminalcauses include adhesions hernias, tumors in adjacent organs, abscesses, and volvulus.

20. Colonic obstruction • Presentation : cause and location • Rectum or left colon ca. Vs. Rt • Regardless of the cause of the blockage, the clinical manifestations of large bowel obstruction include the failure to pass stool and flatus associated with increasing abdominal distention and cramping abdominal pain.

21. The colon becomes distended by gas ( swallowed air, bacterial fermentation), stool, and liquid accumulate proximal to the site of blockage( hernia , volvulus ) blood supply can become compromised, or strangulatedvenousreturn is blockedswellingocclude the arterial supply ischemia  necrosis, or gangrene  perforation • Proximal Segment

22. A closed-loop obstruction occurs when both the proximal and distal parts of the bowel are occluded. • A strangulated hernia or volvulus • cancer occludes the lumen of the colon in the presence of a competent ileocecal valve. • The treatment of large bowel obstruction obviously depends on the cause of the obstruction. • Hx and Ex “ hernia , mass , PR “ • Plain films of the abdomen provide considerable information concerning the location of the obstruction and in some situations may be diagnostic of a volvulus.

23. A CT scan may be helpful in revealing an inflammatory process such as an abscess associated with diverticulitis. If a volvulus or distal sigmoid cancer is suspected, a water-soluble contrast enema may establish the diagnosis. • The treatment options depending on the diagnosis patient stability

24. Colonic pseudo-obstruction (Ogilvie syndrome) • profound colonic ileus without evidence of mechanical obstruction. • It most commonly occurs in critically ill or institutionalized patients. Colonic obstruction or volvulus must be ruled out; Hypaque enema is often therapeutic as well as diagnostic. • The initial management = decompression “ NGT , RT , enema + electrolytes • correction of metabolic disorders, and discontinuation of medications • Neostigmine intravenous infusion (2 mg/hour) in a monitored setting has been shown to be useful in resistant cases (N Engl J Med. 1999;341:137). • Rapid cecal dilation or a cecal diameter greater than 12 cm on plain abdominal X-rays requires prompt colonoscopicdecompression ( 70% to 90%  recurrence rate of 10% to 30 ) • Laparotomy is reserved for patients with peritonitis, at which time a total abdominal colectomy with end-ileostomy should be performed.

25. Diverticular • Diverticulosis + Diverticulitis • Meckelsdiverticulam

26. False • The sigmoid colon • Diverticula are associated with a low-fiber diet and are rare before age 30 years (<2%), • but the incidence increases with age to a 75% prevalence after the age of 80 years.

27. Complications • Infection (diverticulitis). • Microperforationscan develop in long-standing diverticulafecal extravasation peridiverticulitis. • Diverticulitis develops in 10% to 25% of patients with diverticula (90% left-sided, 10% right-sided). • Hx Exis notable for left-lower-quadrant pain, fever, altered bowel habit, and urinary urgency. • Ex severity of the disease, but the most common finding is localized left-lower-quadrant tenderness. The finding of a mass suggests an abscess or phlegmon. • Evaluation by CT scan and complete blood count (CBC) is the standard of care. CT findings may include segmental colonic thickening, focal extraluminal gas, and abscess formation. • sigmoidoscopynor contrast enema

28. Complications • Infection (diverticulitis). • Treatment is tailored to symptom severity. • Mild diverticulitis can be treated on an outpatient basis with a clear liquid diet and broad-spectrum oral antibiotics for 10 days. • Severe diverticulitis is treated with complete bowel rest, IVF , analgesics, and broad-spectrum IV Abx (e.g., ciprofloxacin and metronidazole). If symptoms improve within 48 hours, a clear liquid diet is resumed, and antibiotics are given orally when the fever and leukocytosis resolve. A high-fiber, low-residue diet is resumed after 1 week of pain-free tolerance of a liquid diet. Fiber supplements and stool softeners should be given to prevent constipation. • A colonoscopy or water-soluble contrast study must be performed after 4 to 6 weeks to rule out colon cancer, (IBD), or ischemia as a cause of the segmental inflammatory mass. • recurrenceis 30% 1st and > 50% 2nd of diverticulitis.

29. Complications • Infection (diverticulitis). • Resection should be individualized according to patient lifestyle, tolerance of recurrent episodes and progression to complicated disease with stricture, fistula, or recurrent abscess. • Elective resection • resection + sigmoid colectomy. • Recurrent diverticulitis after resection

30. Complication • Diverticular abscess • CT scan. • A percutaneous drainage + IV Abx • Generalized peritonitis is rare and results if diverticular perforation leads to widespread fecal contamination. • In most cases, resection of the diseased segment is possible (two-stage procedure), and a Hartmann procedure is performed. The colostomy can then be reversed in the future. An alternative in the management of the stable patient undergoing urgent operation for acute diverticulitis without significant fecal contamination is sigmoidectomy, on-table colonic lavage (in the setting of a large fecal load), and colorectal anastomosis with or without proximal fecal diversion (loop ileostomy).

31. Complication • Fistulization • bladder, vagina, small intestine, and skin. • The presentation of enterovesical fistula includes frequent urinary tract infections and often is unsuspected until fecaluria or pneumaturia is noted. • CT findings of air and solid material in a noninstrumented bladder confirm the diagnosis. • A colovaginal fistula is usually suspected based on the passage of air per vagina. • . The presence of methylene blue staining on a tampon inserted in the vagina following dye instillation in the rectum is diagnostic.

32. Complication • Fistulization • Definitive treatment. Colonoscopy is performed after 6 weeks to rule out other possible etiologies, including cancer or IBD. • Elective sigmoid resection is performed after preoperative placement of temporary ureteral catheters.

33. Meckelsdiverticulam

34. Diverticulosis (60%). The media of the perforating artery adjacent to the colonic diverticulum may become attenuated and eventually erode. This arterial bleeding usually is bright red and is not associated with previous melena or chronic blood loss. Bleeding most commonly occurs from the left colon. Urgent resection of the affected colonic segment should be considered in patients with active ongoing bleeding (>6 units packed red blood cells (RBCs)/24 hours). Elective resection of the affected colonic segment should be performed in patients with recurrent bleeding or need for long-term anticoagulation or in those in whom excessive blood loss may be poorly tolerated.

35. Colitis • Ischemic colitis results from many causes, including venous or arterial thrombosis, embolization, iatrogenic inferior mesenteric artery (IMA) ligation after abdominal aortic aneurysm repair, and from acquired P.298

 • or autoimmune vasculopathies. It is idiopathic in the majority of patients. Patients are usually elderly and present with lower abdominal pain localizing to the left and melena or hematochezia. The rectum often is normal on proctoscopy owing to its dual vascular supply. Contrast enema may show thumbprinting that corresponds to submucosal hemorrhage and edema. Diagnosis depends on the appearance of the mucosa on colonoscopy. Although it may occur anywhere in the colon, disease is present most frequently at the watershed areas of the splenic flexure and sigmoid colon. In the presence of full-thickness necrosis or peritonitis, emergent resection with diversion is recommended. Patients without peritonitis or free air but with fever or an elevated white blood cell (WBC) count may be treated with bowel rest, close observation, and intravenous antibiotics. Up to 50% of patients develop focal colonic strictures eventually. These are treated with serial dilations or segmental resection once neoplasm is ruled out. • Radiation proctocolitis results from pelvic irradiation for uterine, cervical, bladder, prostate, or rectal cancers. Risk factors include a dose of greater than 6,000 cGy, vascular disease, diabetes mellitus, hypertension, prior low anterior resection, and advanced age. The early phase occurs within days to weeks; mucosal injury, edema, and ulceration develop, with associated nausea, vomiting, diarrhea, and tenesmus. The late phase occurs within weeks to years, is associated with tenesmus and hematochezia, and consists of arteriolitis and thrombosis, with subsequent bowel thickening and fibrosis. Ulceration with bleeding, stricture, and fistula formation may occur. Medical treatment may be successful in mild cases, with the use of stool softeners, steroid enemas, and topical 5-aminosalicylic acid products. If these measures fail, transanal application of formalin 4% to affected mucosa may be efficacious in patients with transfusion-dependent rectal bleeding. Patients with stricture or fistula require proctoscopy and biopsy to rule out locally recurrent disease or primary neoplasm. Strictures may be treated by endoscopic dilation but often recur. Surgical treatment consists of a diverting colostomy and is reserved for medical failures, recurrent strictures, and fistulas. Proctectomy is rarely required and is usually associated with unacceptable morbidity and mortality.

36. Lower GI bleeding