Your appetite may be affected. If so try to eat several small meals rather than three large meals a day. Drink lots of fluid - try to double your normal fluid intake. If you are worried about diet ask your radiographer to refer you to a dietician.

You may get tired during your radiotherapy course, this doesn't limit your ability to drive but adequate rest is important.

You will probably experience discomfort on opening your bowels (proctitis). Very occasionally this may be associated with some blood and mucous in the stools.  This comes on in the later half of your Radiotherapy .  Steroid suppositories are sometimes prescribed if this is serious.  

If some of your bladder is in the treatment area, you may experience a feeling of wanting to pass urine more often (cystitis). It is still possible to develop a urinary tract infection so drink plenty of fluids and report any burning feeling, on passing urine, to your doctor. Some patient get relief from drinking cranberry juice.

Recent advances in radiotherapy technique have considerably reduced the dose and hence risk of damage to your bowel. Nevertheless, occasionally your bowels may become loose later in the treatment, possibly causing diarrhoea. If this happens, cut down your intake of fruit, vegetables and fibre and try to increase your intake of eggs, milk and other dairy products. Report any diarrhoea to the doctor or radiographer as it may be necessary for you to have tablets. Take these until the diarrhoea improves and then reduce them. Your bowels should have returned to normal 2-3 weeks after treatment. You can then gradually re-introduce fibre into your diet until you are back on a normal diet.

You should continue with your normal diet unless you begin to get diarrhoea.

You may experience a feeling of nausea or sickness may occur during treatment. Report any nausea or vomiting to your doctor as your symptoms can be relieved with anti-sickness tablets. For larger treatment areas you will be given an anti-sickness tablet to prevent nausea.

The skin in the treated area may become red and sore, especially in the skin creases. You can wash by means of a shower during your treatment but it is not advisable to sit and soak in a hot bath and avoid rubbing with a towel or scratching. If any soreness develops report this to the radiographer who will give you advice.

Your acute side-effects usually resolve within 1 month. Very rarely, some people continue to experience tiredness, nausea or loss of appetite for several months.

Some patients will notice that they have to pass urine more frequently than before radiotherapy. The majority of patients do not find these symptoms troublesome even if they persist indefinitely.

Your ability to get an erection (potency) may be affected especially if impaired before treatment or hormone injections were given for > 6 months - ask your doctor about Viagra or similar drugs.

Around 20% continue to have occasional rectal discomfort long term. A few people may also notice occasional blood in the stools. 

Very rarely people may experience more serious side effects (< 0.5%). These include narrowing of the bowel or bladder which may require an operation to correct the damage.