A study looking at side effects of chemotherapy in cancers of the digestive system (FOCCUS)

Cancer type:

Anal cancer
Bile duct cancer
Biliary tree cancers
Bowel (colorectal) cancer
Gallbladder cancer
Liver cancer
Oesophageal cancer
Pancreatic cancer
Small bowel cancer
Stomach cancer





This study looked at the side effects of chemotherapy that affects the tummy (stomach) and bowels.

More about this trial

Chemotherapy is one of the main treatments for cancer. Unfortunately it does cause side effects. Some side effects, such as being sick (vomiting), have been well researched. There are now treatments available so that sickness can be controlled.

This study is looked at how chemotherapy affects your digestive system Open a glossary item, which hasn’t been so well researched.

The aims of this study were to find out:

  • how often chemotherapy affects the tummy (stomach) and bowels
  • why these side effects happen
  • how best to treat side effects of chemotherapy that affect the tummy (stomach) and bowels

Summary of results

The study team found that stomach and bowel symptoms caused by chemotherapy:

  • need active management which isn’t normally done at the moment
  • are often treatable or curable

About this study
People filled in a questionnaire that asked about stomach and bowel symptoms. They filled it in:

  • before starting treatment
  • then every month for a year

Of 241 people, 119 completed all the questionnaires. 

The team also took samples of their blood, urine and poo before treatment. This was to find out:

  • how well their thyroid Open a glossary item was working
  • the level of vitamin B12 Open a glossary item in their blood
  • how well their pancreas Open a glossary item was working

The team offered investigations for people who developed new symptoms or side effects. They told the person's doctor if the results were abnormal.   

During the study more than 20 out of every 100 people (over 20%) reported ongoing inability to control their bowels (faecal incontinence). And more than 10 out of every 100 people (over 10%) reported having moderate to severe problems with:

  • taste
  • swallowing
  • belching
  • heartburn
  • feeling full before completing their meal
  • appetite
  • feeling sick
  • tummy (abdominal) cramps
  • pain around the anus 
  • passing wind (flatulence)
  • rumbling and gurgling in the stomach and bowel
  • urgent need to do a poo
  • feeling of needing to pass poo even though their bowels are empty

The reporting of some side effects increased at the start of chemotherapy. These included:

  • change in smell and taste
  • pain around the anus
  • passing wind 
  • urgent need to do a poo

In the first 6 months of chemotherapy people reported some side effects as staying much the same. By 1 year these were less frequent. These included:

  • bad breath
  • loss of appetite
  • bloating
  • feeling and being sick
  • rumbling and grumblings in the stomach and bowel

Possible causes of the side effects
The samples of blood, poo and urine taken before starting chemotherapy showed that for:

  • 9 out of every 100 people (9%) had a pancreas that wasn’t working well
  • 12 out of every 100 people (12%) showed there wasn’t enough vitamin B12 in the blood
  • 20 out of every 100 people (20%) had a thyroid gland that wasn’t working very well

The team offered further investigations to find out what might be the cause of the side effects. But people often refused the offer. Even so for every 3 investigations done the team identified 1 treatable cause. In particular these were an:

  • overgrowth of bacteria Open a glossary item in the small bowel
  • inability to absorb bile Open a glossary item
  • urine infection

This study shows that bowel symptoms and side effects are common before, during and after chemotherapy. And that they are often treatable. 

They recommend further research through a randomised trial Open a glossary item. They suggest offering specialist supportive care to find out:

  • what effect this has on how long people lived (survival) 
  • how it impacts their quality of life Open a glossary item

The team aren’t doing another study. However another research team did a randomised clinical trial and their results were similar to this study’s results.

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Jervoise Andreyev

Supported by

General Electric
The Royal Marsden NHS Foundation Trust
This study was funded by the friends and family of Lord Philip Gould


If you have questions about the trial please contact our cancer information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:


Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Around 1 in 5 people take part in clinical trials

3 phases of trials

Around 1 in 5 people diagnosed with cancer in the UK take part in a clinical trial.

Last reviewed:

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