Rectal bleeding and haemorrhoids

Chapter 20 RECTAL BLEEDING AND HAEMORRHOIDS




KEY POINTS


Rectal bleeding:


• Initial management of massive rectal bleeding always involves assessment and resuscitation.

• Colonoscopy, radiolabelled red cell scan, selective mesenteric angiography, and computed tomography angiography can be used to identify the site of bleeding. Angiographic embolisation can stop localised bleeding. In stable patients, capsule endoscopy is useful to detect vascular lesions.

• On-table gastroscopy, colonoscopy, and enteroscopy should be considered if the site of massive rectal bleeding is in doubt. Partial or total colectomy may be required if bleeding is not controlled.

Haemorrhoids:


• First-degree haemorrhoids do not prolapse, second degree prolapse on defecation but return spontaneously, third degree prolapse but require manual reduction, and fourth degree prolapse and are not reducible.

• Conservative treatment includes advice to avoid prolonged straining and fibre supplementation. Injection sclerotherapy and rubber band ligation are the two most common interventional treatment options for first- and second-degree haemorrhoids. Haemorrhoidectomy is usually reserved for third- and fourth-degree haemorrhoids.


RECTAL BLEEDING



Causes


Bleeding per rectum can originate from the stomach, duodenum, small intestine, colon or anorectum (Table 20.1). The diagnosis of colorectal neoplasia should be entertained in most cases: 1 in 20 patients over the age of 45 years of age who present with new onset rectal bleeding have colon cancer. The colour of the blood may indicate the source of the bleeding but the rate of bleeding needs to be taken into account. Haematochezia is the passage of bright red blood per rectum and usually indicates bleeding from the distal colon, rectum or anal canal. Dark red blood mixed in with bowel motions usually originates from the small intestine or proximal colon. Melaena, the passage of black tarry stools with characteristic odour, occurs with bleeding proximal to the ligament of Treitz.


TABLE 20.1 Causes of rectal bleeding















Region Causes
Anorectum
• Haemorrhoids

• Anal fissure

• Rectal prolapse/solitary rectal ulcer

• Anal fistula

• Anal varices

• Anal cancer
Colonic
• Diverticular disease

• Angiodysplasia

• Colitis (inflammatory, ischaemic, infective, pseudomembranous, radiation)

• Neoplasia/polyp

• Post-polypectomy/anastomosis bleeding
Other (stomach, small intestine)
• Upper gastrointestinal sources (peptic ulcer, erosions, Mallory-Weiss tear, oesophagitis, varices, neoplasia)

• Small intestine angiodysplasia

• Meckel’s diverticulum and ulcer

Other symptoms are useful to help localise the site of bleeding. Epigastric pain, heartburn and haematemesis or melaena are symptoms associated with bleeding from the upper gastrointestinal tract. Significant weight loss is associated with malignancy and inflammatory bowel disease. Change in bowel habit, tenesmus (feeling of incomplete evacuation) and blood mixed in with faeces are consistent with colonic pathology. Bloody diarrhoea indicates the possibility of colitis. Bright red rectal bleeding not mixed with faeces, blood on the toilet paper and anal pain or discharge are symptoms more indicative of an anorectal source. Personal and family history of colonic polyps, cancer and inflammatory bowel disease are important to elicit.


The site and cause of bleeding can be identified by appropriate investigations such as proctoscopy, sigmoidoscopy, colonoscopy and upper endoscopy. In stable patients, capsule endoscopy is useful to detect vascular lesions. Small intestine endoscopy is worth considering in difficult diagnostic cases with recurrent bleeding (e.g. double-balloon enteroscope).



Causes of massive rectal bleeding


Common causes of massive rectal bleeding include colonic diverticular disease and angiodysplasia. Diverticula in the colon are caused by increased intraluminal pressure together with segmentation of the colon resulting in herniation of mucosa through the muscle wall. Bleeding from diverticular disease is usually a large amount because it results from direct trauma to the adjacent penetrating vessels. It is uncommon for patients to present with diverticulitis and bleeding because the pathogenesis of the two is different. Diverticulitis results from micro-perforation of colonic diverticula. The inflammation is located on the outside of the colon with minimal intraluminal involvement. Ischaemic colitis is a more likely diagnosis if a patient presents with abdominal pain, fever, and rectal bleeding. Angiodysplasia are venous ectasia at the submucosal level and are more frequently found in the right side of the colon. They can be treated with electrocautery or argon plasma coagulation.


Other less common causes include colorectal cancer, colitis, Meckel’s diverticulum, small intestine angiodysplasia and upper gastrointestinal sources. Bleeding from radiation proctitis can be treated with sucralfate enemas, topical formalin or argon plasma coagulation. Bleeding associated with Meckel’s diverticulum is due to ulceration secondary to heterotopic gastric mucosa. Bleeding from an upper gastrointestinal source can be the cause of haematochezia in 10%–15% of cases.

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Mar 29, 2017 | Posted by in GASTROENTEROLOGY | Comments Off on Rectal bleeding and haemorrhoids

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