Rectal bleeding

A patient who bleeds severely from his stomach or duodenum, usually vomits the blood, if he bleeds fast. If he bleeds more slowly, it appears as black tarry melaena stools. The higher the source of the blood, the longer it takes to reach his rectum, and the more likely is it to be converted into melaena stools. Although a melaena stool is usually the result of bleeding from his stomach or his duodenum, it can follow bleeding from his small gut. Dark red ''burgundy-coloured' blood mixed with stool can come from the stomach, the duodenum, the small or the large gut, but fresh bright-red blood usually comes from the rectum or anus. Not all dark stools are the result of bleeding, so remember the possibility of iron medication (negative occult blood test), or nose bleeds (often positive for occult blood).

Bleeding from the upper gut is often severe, is usually more serious than it looks, and frequently threatens his life (11.3). Bleeding from the lower gut is often mild, and even a small quantity of bright blood can be alarming. He is usually not as ill as he seems, and you have more time to investigate him.

Rectal bleeding is common everywhere, but its causes differ geographically. In the developing world, where carcinoma is still comparatively unusual, you can treat most patients with rectal bleeding quite easily.

If he continues to bleed from his rectum, and you are not sure why, you will have to decide: (1) if you are going to operate, (2) when, and (3) what you are going to do when you get inside. In most areas, the commonest cause of massive rectal bleeding is a peptic or duodenal ulcer; but in some tropical areas it is bleeding from the terminal ileum, or ascending colon, due to typhoid or amoebiasis.

The major mistakes are: (1) To misjudge the severity of his bleeding. (2) To fail to use your finger, a proctoscope and a sigmoidoscope, to label him as having ''piles' without examining him properly, to fail to investigate him, and so to miss a carcinoma. (3) To miss the more treatable diseases, such as tuberculosis and amoebiasis, as the following case shows.

POUL (53) had passed several bloody stools since the morning, but had no other gastrointestinal symptoms. He was neither anaemic nor hypotensive, but during the next few days he continued to bleed, and his haematocrit fell to 23%. Sigmoidoscopy showed friable, oedematous, reddish-yellow areas in his rectum, but no obvious ulcers. A smear from his rectal mucosa showed amoebae. Metronidazole cured him dramatically. LESSONS (1) Amoebiasis is readily treatable[md]if you diagnose it. (2) A severe bleed in the absence of previous symptoms of amoebiasis is unusual.


COMMON CAUSES (other than piles 22.4). Peptic ulcer (11.3). Typhoid ulcers of the ileum (bleeding may be severe, 31.8). Amoebiasis (31.10). Schistosomiasis mansoni. Bacillary dysentery (diarrhoea with blood and mucus, 31.10). Anal fissures (which may bleed at defaecation, 22.7). Lymphogranuloma (22.10). Polyps, especially juvenile polyps (usually producing a little fresh blood, see below). Intussusception (''red currant jelly stools', 10.8). Also causes of high gastrointestinal bleeding (11.3).

UNCOMMON CAUSES. Carcinomas of the colon, rectum, or anal canal (32.27), tuberculous ulcers of the gut (29.5), non-specific ulcers of the gut (see below), pigbel disease (31.9), Meckel's diverticulum (episodic massive bleeding in the young, 28.5), rectal prolapse (22.9).

RARE CAUSES. Ulcerative colitis, ischaemic colitis, diverticulitis, haemangiomas of the small gut, blood dyscrasias, villous adenomas of the rectum (bright blood with much watery mucus). A foreign body in the rectum.

EXAMINATION. (1) Assess the degree of the patient's hypovolaemia (53.2), and the severity of his anaemia. Does sitting him up in bed make him feel faint, or exercise make him breathless? Examine him for epigastric tenderness, distension, the signs of subacute gut obstruction (10.3), and abdominal masses.

Examine his rectum with your finger and a proctoscope, and don't forget to look at his stool.

CAUTION ! Never forget to do a sigmoidoscopy if an adult presents with rectal bleeding.

DIFFERENTIAL DIAGNOSIS. Bleeding related to defaecation? (an anal or rectal lesion). Blood mixed with stool? (some lesion higher than the rectum). Painful bleeding? (a lesion below the pectinate line; piles arise above this line and are painless, unless they prolapse or strangulate). A feeling of something prolapsing from the rectum? (piles, prolapse, or polyps). Dyspepsia, heartburn, etc.? (peptic ulceration, 11.1). High fever for a week or two? (typhoid fever, 31.8). Loss of weight, anorexia, night sweats, and fatigue? (abdominal tuberculosis; rectal bleeding is unusual 29.5). Vague lower abdominal pain followed by the passage of much dark blood? (non-specific ulceration of the gut, 22.10). Abdominal pain, diarrhoea, fever, prostration? (non-occlusive infarction of the gut, pigbel disease, 31.9).

THE INDICATIONS FOR LAPAROTOMY. (1) Loss of [mt]1500 ml of blood. If he is in extremis, surgery may be life saving. (2) The presence of a mass. The treatment of most causes of rectal bleeding is discussed elsewhere. Most colonic bleeding stops on its own, so don't operate too early.

RESUSCITATION. Replace the blood he has lost, with due regard to the dangers of HIV (28a.2).

ANAESTHESIA. General anaesthesia.

LAPAROTOMY. Enter his abdomen through a long midline incision. Exclude more common causes of bleeding, such as peptic ulceration, then examine his entire gut from his duodeno[nd]jejunal junction down to his rectum. Note the colour of the contents of his gut. What is the highest site in his gut to show bleeding? Look for abnormal vessels going to the bleeding area, and feel for induration or an ulcer. If necessary, do a gastrotomy and enterotomies (open his gut, 9.3) to find the level of the bleeding.

If he is bleeding severely from his right colon, you don't find a lesion, and there is no bleeding more proximally, consider doing a ''blind' right hemicolectomy (66-20). This will not be easy, so don't do it lightly. Afterwards, open the specimen to see where the blood is coming from.

DIFFICULTIES [s7]WITH RECTAL BLEEDING If a CHILD HAS INTERMITTENT CONTINUING RECTAL BLEEDING, he may have a JUVENILE POLYP. This is a friable, proliferative mass, which lies on his mucosa to begin with, and then develops a stalk. On rectal examination you can usually feel a soft, mobile, pedunculated mass, and see a strawberry-like lesion through a proctoscope or sigmoidoscope. If examination is difficult, you may have to anaesthetize him to examine it.

If a polyp is small, remove it through his anus, tie the stalk, and cut it off. If you cut the stalk without tying it first, it may bleed massively. Or, if tying it is impracticable, leave it to undergo spontaneous strangulation, necrosis, and sloughing.

If the cause of a patient's RECTAL BLEEDING IS NOT IMMEDIATELY OBVIOUS, consider the possibility of NON-SPECIFIC ULCERATION OF THE GUT (uncommon). In the tropics patients sometimes bleed from small punched-out ulcers of unknown cause in the mucosa of their distal ileum and proximal colon. They are usually middle-aged adults of either sex, who present with lower abdominal pain and fever, followed by the passage of a quantity of dark blood rectally. He may be tender in his right iliac fossa; sigmoidoscopy is normal, except for blood coming from above. If bleeding does not stop and you are sufficiently skilled, a right hemicolectomy may save him, because the source of the bleeding is nearly always in his distal ileum, or proximal colon. In good hands he has a 10% chance of death.

His distal ileum and colon are likely to be discoloured by contained blood, and feel slightly oedematous and thickened. The ulcers in his mucosa are rarely palpable.

If you have established the source of the bleeding, and think you could remove it, do an extended right hemicolectomy, and take the last 20 cm of his ileum, his ascending colon, and his entire transverse colon up to his splenic flexure. Do an end to end ileo-transverse anastomosis in two layers.

Open the specimen, and you will find numerous punched-out ulcers in his terminal ileum and right colon, one of which may contain a bleeding artery. Histology shows non-specific changes only, with very little inflammation round the ulcers.

If he has RECTAL BLEEDING ACCOMPANIED BY SEVERE DIARRHOEA, PROSTRATION, vomiting, and fever, consider the possibility of pigbel disease, and see Section 31.9.

Fig. 22-9 LORD'S ANAL STRETCH[md]ONE will cure many cases of piles and anal fissures. First, do a digital examination with your right index finger, then introduce two fingers, side by side. Stretch hard, and then put four fingers in. [f10]Dilate the patient's anus gradually over 3 or 4 minutes, [f11]so that the sphincters of his anus are stretched, and not torn. Finally, put six or eight of your fingers in.