Quick answer: Intestinal obstruction is a blockage that stops food, fluid and gas moving through the small or large bowel. It causes crampy pain, bloating, vomiting and difficulty passing wind or stool. It is a medical emergency because trapped bowel can lose its blood supply and tear, so it needs urgent hospital assessment — go to A&E if you have these symptoms.
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A blocked bowel means the normal onward flow through your intestines has stopped. Some blockages settle with rest and hospital support, but many need surgery, and delay can be dangerous. This guide explains what intestinal obstruction is, how it feels, why it is urgent, and how doctors in Singapore assess and treat it. It is general information and not a substitute for seeing a doctor.
What intestinal obstruction is
Intestinal obstruction is a blockage that stops food, fluid and gas passing through the small bowel or the large bowel (colon). When the passage is blocked, pressure builds up behind it, the bowel swells, and its contents cannot move on. It is a serious condition that usually needs urgent hospital assessment, because an untreated blockage can damage the trapped section of bowel. A blockage can be partial, where a little still gets through, or complete, where nothing passes at all. There is also a type called paralytic obstruction (or ileus), where the bowel is not physically blocked but has stopped squeezing and moving its contents along.
Symptoms
The usual symptoms come on together and tend to worsen:
- Crampy tummy pain that comes and goes in waves, often around the middle of the abdomen.
- A swollen, bloated or distended tummy.
- Vomiting, which may be green (bile-stained) and, if the blockage is low or long-standing, can become foul-smelling.
- Being unable to pass wind or stool — a form of constipation that does not clear.
- Loud, high-pitched bowel sounds early on, which may later become quiet or absent.
- Feeling sick, off your food, and generally unwell.
If the crampy pain becomes constant, severe and unrelenting, this can be a warning that the bowel’s blood supply is affected — a reason to seek emergency care straight away.
What causes it
In adults, common causes include:
- Adhesions — bands of internal scar tissue from previous abdominal or pelvic surgery, which can kink or tether the bowel. This is one of the most frequent causes.
- Hernia — a loop of bowel pushing through a weak spot in the abdominal wall and becoming trapped.
- Bowel cancer — a tumour narrowing or blocking the colon, sometimes the first sign of the disease.
- Volvulus — a twisted segment of bowel that closes off the passage and its blood supply.
- Diverticular disease — inflammation and scarring that narrow the colon.
- Faecal impaction — a hard, stuck mass of stool, more common in older or less mobile people.
In babies and children, the causes are different and may include conditions the bowel is born with or a segment telescoping into itself. A paralytic type, where the bowel simply stops moving, can also follow surgery, infection or certain illnesses.
Why it is urgent
Behind the blockage, the bowel stretches and pressure rises. This can squeeze off the blood supply to that section, so the tissue begins to die. A starved or trapped loop of bowel can tear (perforate), spilling its contents into the abdomen and causing serious, spreading infection. Fluid and salts are also lost, which can make a person very unwell quite quickly. Because these problems can develop within hours, a suspected obstruction should always be assessed urgently in hospital rather than watched at home.
How it is diagnosed
A general or colorectal surgeon will start with your history and an examination of your abdomen, feeling for tenderness, swelling and hernias, and listening for bowel sounds. Imaging confirms and locates the blockage: an abdominal X-ray can show loops of dilated bowel and trapped gas, while a CT scan gives more detail on where the blockage is, what is causing it, and whether the bowel’s blood supply is threatened. Blood tests check for dehydration, infection and the effects on your salts and organs. In Singapore this assessment happens in a hospital A&E, with admission under a surgical team at centres such as SGH or NUH.
Treatment
Initial treatment is supportive hospital care to rest and decompress the bowel. This usually means nothing to eat or drink by mouth, fluids and salts given into a vein through a drip, and a thin tube passed through the nose into the stomach to drain fluid and gas and relieve the pressure and vomiting. You will be monitored closely. Some blockages — particularly those from adhesions — settle with this approach alone as the bowel recovers.
Many people, however, need an operation to relieve the blockage and treat its cause: dividing adhesions, repairing a trapped hernia, untwisting or removing a segment of bowel, or dealing with a tumour. If part of the bowel has been damaged, it may need to be removed, and sometimes a temporary stoma is formed to let the bowel heal. The right treatment depends on the cause, how unwell you are, and what the imaging shows, and your surgical team will discuss the options with you.
Recovery and prevention where possible
Recovery depends on the cause and whether surgery was needed. After the bowel starts working again, eating and drinking are reintroduced gradually. Preventing a future blockage means treating the underlying problem: repairing hernias, keeping constipation under control with good fluid intake, fibre and, where advised, gentle laxatives, and following up on any bowel cancer or diverticular disease found. Adhesions cannot always be prevented, so it helps to know the warning signs and act early if they return. Keep any follow-up appointments and tell your doctor promptly if symptoms come back.
When to seek emergency help
Go to A&E or call 995 if you have severe or worsening tummy pain with a swollen, bloated tummy, persistent vomiting (especially green vomit), and cannot pass wind or stool. These point to a possible bowel obstruction, which is a surgical emergency. Do not eat or drink, and do not delay — earlier treatment gives the best chance of avoiding damage to the bowel.
Common questions
Can a bowel obstruction clear on its own?
Some partial blockages, especially those caused by adhesions, settle with hospital rest, drip fluids and a decompression tube. But you cannot tell which will settle without assessment, and a complete blockage will not clear at home, so any suspected obstruction needs urgent medical care.
Is it the same as bad constipation?
No. Ordinary constipation is difficulty passing stool, while an obstruction is a physical blockage that also stops wind and is usually accompanied by cramping pain, a swollen tummy and vomiting. Severe, prolonged constipation can, however, lead to a blockage from impacted stool.
Why should I not eat or drink if I might have an obstruction?
Anything you swallow adds to the fluid and pressure building up behind the blockage, which can worsen vomiting and raise the risk of choking. It also keeps you ready for any procedure or operation, so it is safest to stay nil by mouth until seen.
Does an obstruction always mean surgery?
Not always. Many people improve with supportive care alone, but a significant number need an operation to relieve the blockage and fix the cause, particularly with a trapped hernia, a twisted bowel or a tumour.
Which doctor treats a blocked bowel in Singapore?
It is managed by a general or colorectal surgeon, usually after you are seen in A&E and admitted to a surgical team at a hospital such as SGH or NUH.
Related guides
Sources
- Singapore General Hospital
- HealthHub
- NHS
- American College of Gastroenterology