Incisional hernia: symptoms, causes and repair after surgery

Symptoms depend on where the hernia is and how long it has been there. The NHS lists a bulge or lump at the site, which may get bigger when you cough, sneeze or cry and smaller when you lie down, skin over the lump that looks tight and stretched, and pain in or around the hernia, which is usually noted with smaller hernias and can be a sign of strangulation. It also points out that a large hernia may look uncomfortable but not be painful, because the stretched muscle lets it pass through easily.

In practice many people first notice a soft swelling along or beside a scar that is more obvious when standing, straining or lifting. Because the lump can go back in when lying flat, the hernia can be intermittent at first.

• A bulge along or next to an operation scar

• A lump that grows with coughing or straining and shrinks when lying down

• Aching or discomfort around the scar, often worse with activity

• Skin over the lump looking tight or stretched

• A sudden hard, tender, painful lump that cannot be pushed back, which is an emergency sign

The NHS tells people with a hernia to get help from NHS 111 if they have pain in or around the hernia, a bloated tummy, nausea or vomiting, vomiting blood or vomit that looks like coffee grounds, constipation, a high temperature or feeling hot, cold or shivery, or sudden confusion. These can indicate that part of the bowel has become trapped, which the NHS trust leaflet calls the most serious complication, strangulation, causing severe pain and vomiting.

The leaflet advises going to your local accident and emergency department as soon as possible if those symptoms develop. If you are severely unwell, cannot keep fluids down or the pain is intense, call 999. Do not wait to see whether it settles.

A hernia is where part of an internal organ, such as the bowel, pushes through a gap or weak area in the muscle that holds the organs in place. An incisional hernia is the type that forms at or near the scar of a previous operation. An NHS trust patient leaflet describes it as a weakness, separation, gap or opening in the muscles or supporting structures of the abdominal wall right at, or in the region of, a surgical incision, which may cause a bulge and or pain and discomfort.

The NHS hernia page does not give incisional hernia its own heading, but it does list stoma hernia, a hernia under or near a stoma. It also explains that most hernias develop in the tummy or groin, that some cause a lump under the skin while others are internal, and that treatment depends on the type, its cause and whether it is new or has come back after treatment.

Surgery involves repairing the area of weakness and returning the abdominal contents to their normal position. The leaflet describes mesh repairs, where a piece of mesh is placed over the repaired hernia to give extra strength, and a repair for large hernias in which one, sometimes two, pieces of mesh reinforce the defect. It says the operation is done under general anaesthetic, and in that trust it is planned as a day case, so most patients go home the same day.

Recovery details in the leaflet include pain relief for the first couple of days and then as needed, keeping the dressing in place, support of the wound with a hand when coughing, and gradual walking to reduce the risk of chest infection and clots. It says two to four weeks off work is usual, that mesh repairs allow normal activities from two weeks, with no heavy lifting for six weeks, and that driving should wait until the wound has healed and you can do an emergency stop. These timings come from one trust, so your surgeon's instructions take precedence. The NHS inguinal hernia repair page, which concerns another site, gives a similar shape of recovery with 4 to 6 weeks for heavy activity.

The leaflet attributes an incisional hernia to weakness or separation of the abdominal wall at the surgical site, and it says that the bigger a hernia becomes, the more likely complications are. The sources read for this guide do not give figures for how common incisional hernias are or rank individual risk factors, so none are quoted here.

Prevention advice from the NHS for hernias in general applies as a sensible precaution after abdominal surgery: keep to a healthy weight if you are overweight, be physically active, aiming for at least 150 minutes of moderate activity or 75 minutes of vigorous activity a week once your surgeon says you are able, try to stop smoking, and see a GP about a cough that does not get better or keeps coming back. Straining is something the trust leaflet asks patients to avoid after an operation, advising plenty of fluids and fibre and a mild laxative if needed.

The NHS advises seeing a GP if you think you have a hernia, and says they may refer you for tests or treatment if needed. The sources read for this guide do not describe the examination or scans used for an incisional hernia, so what is arranged for you is a matter for the clinician who assesses you. If a lump near a scar is new, growing or uncomfortable, ask for it to be examined rather than waiting.

The trust leaflet notes that when surgery is not an option because a person is high risk or has no symptoms, a hernia may be managed with or without an abdominal binder, which is a pressure belt. Whether to operate is a shared decision that weighs symptoms, size, other health conditions and the risk of complications.

Most people are referred by a GP to a general or hernia surgeon, and some choose to see a private surgeon through insurance or self-funding. Ask the surgeon how many repairs of this type they do, whether mesh would be used, the approach (open or keyhole) and what the follow-up arrangement is. Waiting times and access differ by area, and the British Hernia Society, which promotes safe, effective and high quality hernia surgery in the UK, publishes hernia information for patients and the public.