The GI Tract

The gastrointestinal tract (or GI tract) is the term for the esophagus, stomach and the small and large intestines and is the passage for food through the body. CF can affect the GI tract in different ways. In general, the intestines are impacted in a similar way as the lungs or sinuses, with abnormal mucus which is thicker and stickier than normal.

Problems with the GI tract in CF include:

  • Distal intestinal obstruction syndrome (DIOS): partial or total blockage of the bowel due to thick mucus, undigested fat and stool.
  • Gastroesophageal reflux disorder (GERD): acid reflux or heartburn
  • Small bowel bacterial overgrowth (SBBO)
  • Cancer

It is important to tell us about any problems so that we can work with you to determine what is going on and treat it effectively. If you have any change in your bowel routine please tell us as this may be an early sign that something is going on.

About 5-10% of people with cystic fibrosis get DIOS.

The main symptom of DIOS is abdominal pain, often on the right lower side of your abdomen. The pain is crampy (comes and goes) and is often worse after eating. You may not feel as hungry as you usually do, or you may feel full sooner after eating. You may notice that you are having fewer bowel movements or that you still feel full after having a bowel movement.

What causes DIOS?

DIOS is caused by a combination of thick mucus and undigested fat from food getting stuck in the intestine, often where the small bowel and large bowel meet on the right lower side of the abdomen. The pain is due to contractions in the wall of the bowel as the body tries to push this thick sticky stool through the intestines. Factors that can contribute to DIOS include not taking enough pancreatic enzymes and being dehydrated. DIOS is more common in people with CF who had meconium ileus at birth or who have had surgery to their bowel. Some patients with cystic fibrosis get DIOS more often than others. You can still get DIOS when you take your enzymes properly. DIOS is similar to but not the same as constipation and does not exist except in people with CF.

DIOS is diagnosed by taking a history and feeling your abdomen. The diagnosis is confirmed with an X ray.
If you have a pain in the stomach that you think might be DIOS, call your CF clinic. If your DIOS is more severe, you may vomit and have more severe pain. If this happens, go to the emergency department of the hospital nearest to your home for treatment. Also call the CF doctor on call so we know you are unwell and can speak to the doctor at the emergency department.

How to treat and prevent DIOS

The thick mucus and stool must be washed out of your bowel using the same prep as is used for a colonoscopy (Peglyte or Golytely or Colyte). It usually takes 4 to 8 litres of Peglyte over a 4 to 8 hour period. This can be done at home. If you cannot drink all the Peglyte due to nausea or vomiting, you may need a tube put through your nose into your stomach. This tube is called a nasogastric, or NG, tube. You will then get the Peglyte through that tube. Usually you will have this treatment during the day in hospital.

Strategies to prevent DIOS from occurring include: adjusting pancreatic enzyme dose with the amount of fat ingested and regular use of PEG3350 (Restoralax or Laxaday) taken with 500ml – 1 litre of fluids. Some people will need medications to assist bowel motility and help food move through your intestines. The doctor or nurse in the cystic fibrosis clinic will tell you what the best option is for you.

Click here for instructions on how to complete an effective bowel clean out for DIOS or constipation.

People with cystic fibrosis have a higher chance of developing cancer in their gastrointestinal tract, which includes the colon, esophagus, small bowel, pancreas, liver and bile tract. The increased risk starts earlier in life than in people who do not have CF.

Colon cancer is the most common cancer seen in CF. Screening for colorectal cancer can detect abnormalities before they become cancerous and thus cancer can be prevented or detected it in the early stages. Recent guidelines recommend screening people with CF with a colonoscopy starting at the age of forty. For people with CF who have received a transplant, the risk of cancer is greater and screening colonoscopy should start at age 30 years.

Other screening tests may be indicated if you have specific symptoms or if a relevant family history of bowel cancer is present. Ask your CF team for more information on this important topic.

Small Intestinal Bacterial Overgrowth (SIBO) happens when there are excessive bacteria in the small intestine. In CF, bacteria can become “trapped” in the small intestine by excessive mucus and the slow movement of food and waste products through the digestive tract. Symptoms of SIBO can include bloating, diarrhea, abdominal pain, gas and/or weight loss. Treatment is usually with an antibiotic that helps kill bad bacteria to allow normal bacteria to grow and repopulate in the intestine. The CF team will often recommend cycling the antibiotic in a 2 weeks on-off regimen to decrease the risk of developing bacterial resistance to the antibiotic. The use of polyethylene glycol (PEG)-based laxatives may also be help decrease bacterial overgrowth.

There are many reasons why people with CF may be prone to gastroesophageal reflux disease. Some of these include, abnormal relaxation of the lower esophageal sphincter (the muscle at the bottom of the esophagus where it meets the stomach), increased abdominal pressure due to chronic coughing, medication side effects, and possibly mechanical effects of over-inflated lungs pushing down on the diaphragm.