DISORDERS OF THE RECTUM AND ANAL CANAL

THE RECTUM AND ANAL CANAL

 

1. Haemorrhoids- Painful anal condition characterisd by protrusion of the anal mucosa. It is caused by constipation associated with passage of hard stool. Predisposing factors include;

· Food low in fibre

· Taking less oral fluids

· Disease conditions such as cancer of the colon and HIV/AIDS

· Other painful anal conditions which might cause patient to avoid defeacation e.g fissure in ano,fistula in ano, peri ano warts etc

· Pregnancy usually in second and third trimesters

Classified into 3 types

(i). First degree haemorrhoids- The haemorrhoids are internal (localized in the anal canal).They do not come out during defeacation.

(ii). Second degree haemorrhoids- These come out during defeacation but return into the anal canal thereafter.

(iii).Third degree haemorroids- These haemorrhoids come out and remain trapped outside the anal canal.They have a tendence to thrombose.

 

Complications

· Bleeding

· Thrombosis

· Ulceration

 Treatment

First and second degree haemorrhoids are managed conservatively by high fibre diet and lots of oral fluids. If they persist, stool softeners such as dulcolax is prescribed in addition.

Third degree haemorrhoids are treated surgically by haemorrhoidectomy. If thrombosed, evacuated the clots.

 

2. Anal fissure- It is a painful anal tear which does not heal easily due to repeated tearing during defeacation and poor hygine. It is caused by passage of hard stool causing tearing.Tearing can occur at any point of the anal canal but posterior and anterior tears are the commonest.

        Treatment 

(i). Manual dilatation of anus(MDA) in theatre

(ii). Scrapping of the base of the fissure and injecting nitroglycerate.

(iii). Sitz baths after any of above procedures,  then to take high fibre diet and lots of oral fluids.

 3. Anal fistula (fistula in ano)-It is a fibrous tract(tunnel) from either the anal canal or the rectum and opening up on the skin near the anus.Contents of the rectum or anal canal continuously drain onto the peri anal area even when anus is closed.Therefore the anal area is always wet, itchy and very painful.It usually develops from a poorly managed peri anal abscess or rectal ano abscess.Also common in immunosuppressed patients e,g HIV/AIDS,DM 

Classification

Low level fistula in ano-from below internal anal sphincter muscle

High level fistula in ano- from the internal anal sphincter muscle

 

Treatment

(i). conservative management with sitz baths, antibiotics and treatment of the underlying cause e.g chronic abscess, TB,HIV/AIDS, DM etc

(ii). Fistulotomy for low level fistulae

(iii). Fistulectomy for both low and high level fistulae in ano

 

Complications of surgery

· Wound infection especially for immunosuppressed patients

· Feacal incontinence if internal anal sphincter muscles is damaged.

 

4.Ischiorectal  abscess-An abscess occurring between ischium and rectum. This region contains a lot of fat and has a poor blood supply. Poor blood supply results in treatment of abscess in this area very difficult. There is a high rate of recurrence if the abscess is not drained properly. A cruciate incision should be made in orlder to drain the abscess properly. 

5. Cancer of the rectum-Second commonest tumour of the gastrointestinal tract after cancer of the oesophagus. Histological type is mainly adenocarcinoma. (arises from grandular tissue)

 Risk factors

 

· High fat low fibre diet

· Common above 50 years

· Family history(First degree relatives)

· M > F

 

Staging; Staged A to D

 

A- Cancer confined to rectal wall

B- Cancer has spread to tissues around the rectum

C- Cancer has spread to lymph nodes around the rectum

D- Cancer has spread to distant organs e.g liver, lungs, bones etc

 

Symptoms

· Bleeding per rectum

· Vague lower abdominal pain

· Change in bowel habit-diarrhoea, constipation

· Weight loss

 Management

 

Take patient to theatre for examination under anaesthesia (EUA) of the anus, anal canal and rectum. If mass is palpable (usually hard), collect a biopsy for histopathology.

If histopathology confirms cancer,stage the disease. For stage A and B, resect the tumour (abdominal perineal resection -AP). Stage C and D means the cancer is advanced, hence treat patient palliatively.

 

6. Hirschprung disease- It is a congenital condition condition (chromosomal deletion) affecting the intestines.  It is characterized by dilatation of a segment of the intestine usually the colon due to lacky of ganglions. No peristaltic movements occur in this segment, so digester turn to accumulate resulting in severe constipation. The condition usually presents at the age below one year.

 

Diagnosis

a. Abdominal x-ray show a distended intestinal segment

b. Rectal biopsy shows absence of ganglions

Treatment

Laparotomy, then resection of the affected segment followed by end to end anastomosis.

 7. Special investigations

 (a). Proctoscopy- It is physical examination of the rectum using an instrument called proctoscope. This instrument is pushed through the anus into the rectum .By direct viewing of the rectum, one is able to the contents and walls of the rectum, pathologies such as ulcers,masses.  polyps and tumour masses can be seen. Biopsy can also be collected under direct vision. Proctoscopy is performed when the rectum is emptied by  keeping the patient on fluid diet for at least 48 hours.

 (b). Colonostomy- It is  physical examination of the contents and walls of the colon using an instrument called colonoscope. This flexible instrument is pushed into the colon through the anu and the 1.5 meters stretch of the colon is examined.

Pathologies such as ulcers, polyps and tumours can be examined for. Biopsy can also be collected. The commonest complication of this procedure is intestinal perforation. Therefore care must be taken when performing the procedure.

 

©. Barrium enema- This investigation allows viewing of the on intestines on an x-ray taken after a contrast media has been pushed or allowed to flow into the intestine through the anus.In preparation for the procedure ,the patient should be on fluid diet for atl east 48 hours. Localised constrictions, dilatations or obstruction of the intestines can be seen.

8. Spegcial procedures

(a). Rectal lavage- Basically involves clearing of the rectum to facilitate proctoscopy. Lavage is preceeded by keeping the patient on fluid diet for at least 48 hours. The residues are removed by lavage that is flashing and withdrawing of fluid by use of a big syringe e.g a 60ml syringe.

 (b). Enema administration-patient kept on fluid diet in order to clear the all the intestinal contents.

i). A special syringe is used to inject the contrast through the anus into the intestines.The patient has to be placed with buttocks raised.Then 2 or 3 x-rays are taken periodically.

 ii). Patient is placed with buttocks raised then the drip of the contrast is allowed to ran through the anus.The x-rays are also taken periodically.