Chronic intestinal pseudo-obstruction (CIPO): symptoms, diagnosis and treatment

Guts UK describes CIPO as an overall term for several rare conditions which can affect any part of the gut but primarily the small intestine. The symptoms are those of a bowel obstruction, such as swelling, pain and vomiting, but scans and other tests show no physical blockage. Instead, the muscles that push food along, or the nerves that coordinate them, are not working properly.

Normally the gut moves its contents along with coordinated waves of muscle contraction known as peristalsis. In CIPO, Guts UK says the contractions are weak or uncoordinated and the contents do not move through properly. When a specific abnormality of the gut nerves or muscles is found, terms such as visceral myopathy (bowel muscle dysfunction), visceral neuropathy (bowel nerve dysfunction) and mesenteric plexitis may be used, all of which fall under the CIPO umbrella.

CIPO is different from gastroparesis, in which the NHS describes food passing through the stomach more slowly than it should. CIPO mainly concerns the small intestine, although the two are related motility problems.

Guts UK lists pain, nausea and vomiting, bloating and distension, feeling full very quickly, heartburn and reflux, and a change in bowel function such as constipation, diarrhoea or both. Weight loss and malnutrition can follow, and the symptoms can be frequent or constant, affecting family, work and social life.

The NHS lists signs of malnutrition that are relevant here: unintentional weight loss, with losing 5% to 10% or more of weight over 3 to 6 months described as one of the main signs, a low body weight, a lack of interest in eating and drinking, feeling tired all the time, feeling weak, and getting ill often and taking a long time to recover.

Guts UK also acknowledges the psychological toll, noting that recurrent severe symptoms with no clear diagnosis can cause major upset and feelings of hopelessness, and that patients should tell the doctor if they feel this way so support can be organised.

In most people, Guts UK says, the cause of the damage is not clear. When a cause is found it may be another disease not related to the gut, including autoimmune conditions such as lupus and rheumatoid arthritis, diabetes or an underactive thyroid, neurological disorders such as Parkinson's disease, and connective tissue diseases such as systemic sclerosis.

Rarer triggers include infections such as herpes viruses, abdominal surgery, some forms of cancer, and certain medicines such as opioids, including codeine, tramadol, morphine, buprenorphine, tapentadol and fentanyl. Guts UK warns not to stop any medication without discussing it with your doctor. In some people it has a genetic component and runs in families, and it can rarely affect infants and children, where the cause often runs in families.

Diagnosis is often slow. Guts UK says that in many cases the diagnosis is made only after a long delay and despite many unhelpful investigations. The first task is to exclude a true mechanical obstruction. Guts UK lists an abdominal X-ray, CT scan, barium small bowel follow-through and MR enterography, which help rule out a blockage and will typically show an enlarged (dilated) intestine.

If scans show nothing unusual, transit studies may be performed to see how content travels through the gut, and pressure studies (manometry) are rarely used to measure gut contractions. Blood tests look for anaemia, infection, hormone levels and antibodies and help establish whether a cause can be found. A biopsy of the gut, so the muscles and nerves can be examined under a microscope, is not frequently undertaken because it usually involves surgery, which has its own risks and rarely changes treatment.

Guts UK stresses that in many cases all results apart from the dilated bowel will be normal, meaning an exact cause is often not found, which is called idiopathic. Because the condition is rare, referral to a gastroenterology service with experience of gut motility disorders is often needed.

Guts UK says treatment is usually individual and can be challenging, involving a gastroenterologist, a dietitian, a pain management team, a psychologist and occasionally a surgeon. If CIPO is due to another condition, treating that underlying disorder is important.

Diet and nutrition come first. Guts UK says people are generally advised to eat small meals often rather than three large meals a day, and to work with a dietitian specialising in gastroenterology. If adequate nutrition cannot be maintained by eating, other feeding methods may be needed, such as nasogastric or PEG tube feeding, or parenteral nutrition delivered directly into a vein, which is considered only in severe cases because of its side effects. The NHS describes a similar ladder for malnutrition: fortified foods, nutritional drinks or supplements, then a feeding tube or nutrition given into a vein if eating cannot be managed.

Medicines do not cure CIPO but help symptoms. Guts UK names prokinetics, which increase gut movement, such as domperidone, metoclopramide, erythromycin, octreotide and prucalopride, together with anti-sickness medicines and painkillers. It warns that morphine and morphine derivatives such as codeine can make symptoms worse and should generally be avoided. Low-dose antidepressants and gabapentin may be used for chronic pain, and small intestinal bacterial overgrowth, a common complication, may need antibiotics.

If the gut becomes very large and does not respond to medicines, excess gas may be removed by decompression using tubes or a venting PEG. Surgery is reserved for severe cases and rarely performed because CIPO normally affects the whole gut, though it may be used for a venting stoma or to remove a limited section, and intestinal transplantation is considered only extremely rarely.

Because CIPO mimics obstruction, a flare can be difficult to tell from a true blockage. Seek urgent help (NHS 111, or A&E and 999 if severe) for sudden severe tummy pain, repeated vomiting that you cannot keep fluids down with, vomiting that looks like coffee grounds or smells of faeces, blood in vomit or stool, a rigid or rapidly swelling abdomen, fever, or signs of dehydration such as very dark urine and dizziness. The NHS gastroparesis page lists sudden severe tummy pain, blood in the vomit and dark brown or black vomit resembling coffee grounds as reasons to call 999 or go to A&E, and the same logic applies.

If you have a feeding tube or parenteral nutrition line, use the contact details your team gave you for problems with the tube, line site infection or fever.

Guts UK says that if symptoms are well controlled, regular follow-up is not necessary, but if symptoms are ongoing, regular follow-up helps to consider new treatments and monitor nutrition. If you receive nutritional support, regular review by a doctor, dietitian or nutrition nurse is important to monitor weight and check that the feeding regime is adequate.

The outlook varies. Guts UK says that for some people medicines alone may be helpful, but in general people with CIPO tend to have ongoing symptoms despite treatment, and in some cases the condition is progressive. It describes research as urgently needed, with more specific medicines and bowel pacemakers as possible future options.

Guts UK points people to PORT, the Pseudo Obstruction Research Trust, a charity that supports people diagnosed with CIPO. Questions worth taking to your appointment include whether CIPO has been thoroughly investigated, whether you can be referred to a dietitian, what pain relief to use at home and in hospital, and how often follow-up is needed.