Bowel cancer and fatigue

Fatigue is often confused with tiredness. Tiredness happens to everyone - it is the normal feeling you expect after certain activities or at the end of the day. Usually, you know why you are tired and a good night's sleep solves the problem, but this is not the case for many people with bowel cancer.

Fatigue is a daily lack of energy; it is excessive whole-body tiredness not relieved by sleep. It can last for a short time (a month or less) or stay around for longer (one to six months or even longer). Fatigue can prevent you from functioning normally and gets in the way of things you enjoy or need to do.

Cancer-related fatigue is one of the most common side effects of bowel cancer and its treatment. It is not predictable by tumour type, treatment, or stage of illness. Usually, it comes on suddenly, does not result from activity or exertion, and is not relieved by rest or sleep. It is often described as "paralysing" and may continue even after treatment is complete.

What causes fatigue with bowel cancer?

The exact reason for bowel cancer-related fatigue is unknown. It may be related to the disease itself or its treatments.

The following bowel cancer treatments are commonly associated with fatigue:

Chemotherapy. Any chemotherapy medication or regimen may cause fatigue. Fatigue usually develops after several weeks of chemotherapy. In some, fatigue lasts a few days, while others say the problem persists throughout the course of treatment and even after the treatment is complete.

Radiation therapy. Radiation, commonly used in the treatment of bowel cancer, can cause fatigue that increases over time. This can occur regardless of the treatment site. Fatigue usually lasts from three to four weeks after treatment stops, but can continue for up to two to three months.

Combination therapy. More than one cancer treatment at the same time or one after the other increases the chances of developing fatigue.