Internal organs in the abdominal cavity are covered by protective layer of muscle and connective tissue known as fascia. Any weak spot in the muscle can rupture through which the content inside the abdominal cavity like intestine or fatty tissues can protrude outward and develop hernia. 

A hernia can be caused by weakness of the abdominal wall, any incision or scar or congenital predispositions. The defect cannot be treated by medical management. Surgical intervention is required to treat hernia. A reducible hernia is one which can be pushed back into the opening.

All hernia should be treated on time regardless of small and asymptomatic hernia. After examination surgeon can identify the characteristics of hernia that may produce high risk of developing problem such as incarnation or strangulation. Sometimes the hernia neck opening in the muscle is quite small and hernia sac is large, this can create emergency situation if hernia sac gets trapped in the small neck opening

Hernia Classifications

1. Inguinal Hernia

2. Femoral Hernia

3. Ventral Hernia

4. Umbilical Hernia

5. Paraumbilical Hernia

6. Hiatus Hernia

7. Spigelian Hernia

8. Lumbar Hernia

Inguinal hernia or groin hernia is estimated to be 27 to 43 percent in males and 3 to 6 percent in females1. Inguinal hernias are more common in men. Inguinal hernia occurs when abdominal tissues or intestine bulge out through a weak spot in the muscle of the abdominal wall around the groin area. In men, the spermatic cord pierces the muscle and in females, the round ligament pierces the muscle. Inguinal hernia can be bilateral or single-side.

Direct Inguinal Hernia: A Hernia sac can penetrate through the wall of the inguinal canal due to Increased intra-abdominal pressure or cough or straining can cause direct inguinal hernia

Indirect Inguinal Hernia: This kind of hernia is congenital, Inguinal Canal fails to close before birth and abdominal contents protrude through the internal inguinal ring into the inguinal canal and may extend into the scrotum in the male or extend into the skin fold at the vaginal opening in the females

As compared to inguinal hernia, femoral hernia cases are very few and account for approx. 3% of total groin hernias. The incidence of femoral hernia is 10 times higher in females than males. A femoral hernia develops when the abdominal contents pass through a weak spot known as the femoral canal during pregnancy or childbirth. The bulge or hernia sac in the femoral hernia appears near the groin, upper thigh, or skin folds surrounding the vaginal opening. The femoral hernia should be repaired on a priority basis, as it is associated with a high risk of strangulation, where the intestine can be trapped in the hernia sac and blood supply to the intestine can decrease.

Ventral Hernia occurs when the intestine or abdominal tissues protrude through a weak ventral muscle at any location on the abdominal wall.

Three common types of ventral hernia are:

1. Incisional Hernia: An abnormal protrusion along or close to the surgical scar

2. Periumbilical Hernia: This hernia occurs around the navel area

Epigastric Hernia: This hernia occurs in the epigastric region above the belly button and below the sternum.

Umbilical Hernia: Protrusion of bowel content through a defect in the abdominal wall near belly button

Hiatus Hernia: When stomach bulges into the chest through the opening or weakness of diaphragm muscle hiatus hernia can occur

Irrespective of the site hernia can be classified into following:

1. Reducible Hernia: When the lump or bulge can be gently reverse or push back to original place through the opening of weak muscle known as reducible hernia

2. Irreducible Hernia: When the content of the hernia cannot be pushed back in the abdomen is known as irreversible hernia

3. Incarcerated hernia: In this hernia bulge cannot be pushed back and intestine or tissue trapped in the hernia sac and can cause obstruction

4. Strangulated Hernia: A hernia is strangulated if the intestine is trapped in the hernia pouch and the blood supply to the intestine is decreased due to compromised blood supply. This is a surgical emergency.

Causes of Hernia

Increased abdominal pressure is the most important factor for developing hernia. It could be because of pregnancy, ascites, cough, COPD straining

The most common causes of hernias in adults are:

• Pre-existing weakness of the abdominal wall

• Straining such as during child birth or weight lifting

• Chronic constipation

• Obesity

• COPD

• Enlarged prostate (Straining during urination)

• Chemotherapy drugs and corticosteroids 

• Surgical site infection 

• Repetitive vomiting

• Increased intra-abdominal pressure

• Pregnancy

Signs and symptoms

• A protrusion or bulge in the abdominal wall or groin area, increases during physical activity and decreases while lying down

• Dull ache or Pain in the protruded area (worse with activities)

• Vomiting and constipation

Symptoms of a strangulated hernia

• Abdominal distension, tenderness, and pain

• Discoloration of the skin around protruded area 

• Vomiting

• Constipation

Diagnosis

• The primary diagnosis of any hernia is clinical examination. The bulge become more prominent while coughing .90 % of hernia can be diagnosed through physical examination.

• Ultrasound

• MRI or CT scan

These imaging test confirm the size of the defect and determine nature of the contents of the hernia

Treatment

All hernias should be repaired however if the hernia is small and asymptomatic sometimes that hernia can be watched regardless it’s a good idea to consult a specialist if you have been diagnosed with hernia because specialist or hernia surgeon will be able to examine and identify the characteristics of the hernia that may put you a higher risk of developing problems such as incarnations or strangulations (Sometimes hernia neck or opening in the muscle is quite small but the hernia sac or the contents that protrude into can be rather large, so in that instance incarnation or strangulation can occur ). In such situations surgery is recommended even if hernia is not symptomatic. 

Medical management of hernia treatment is not available. Once the defect occurs surgery is the only treatment choice. 

Advanced hernia surgery in Delhi can avoid the complications due to hernia defects. Delaying the hernia surgery can increases the defect, smaller hernia surgery is less complex while bigger hernia increases the complexity of surgery and increases the recovery time.

In some cases, delayed hernia surgery can become life-threatening and require emergency surgery like strangulated hernia

The goal of Hernia Surgery

1. The goal of fixing a hernia is to less damage to tissue as possible to get the best possible result

2. The patient can resume day-to-day work very soon

Important steps in the hernia surgery

• 1st Step is to reduce the content back into the abdominal cavity

• The second step is to repair the hole by sutures

• 3rd step is to reinforce the repair by putting the mesh. By putting the mesh recurrence rates are much lower

Surgical approach for hernia surgery

1. Laparoscopic Hernia Surgery

2. Open Hernia Surgery

1. Laparoscopic hernia surgery is a surgical procedure used to repair hernias. In laparoscopic hernia surgery through small incisions, trocars are inserted into the abdomen. A camera is inserted through the trocar to see the magnifying view of hernial contents (omentum or intestine) on a monitor and the surgeon can start surgery to reduce the defects, finally, hernia defects is fixed with non-absorbable sutures and adequately sized mesh,

Advantages of laparoscopic hernia surgery

1. Hernia defects can be fixed with small incisions, patient experiences less pain, faster recovery, early healing, and small scars.

2. In laparoscopic hernia surgery, the laparoscope magnifies the internal view, this gives a better view to the surgeon compared to open surgery.

3. In laparoscopic hernia surgery there is less manipulation of tissues, so patients will experience less pain..

4. Laparoscopic hernia surgery can help the patient to be discharged early and a patient can resume normal activities within a very short period

Open hernia Surgery

Open hernia surgery in Delhi can be performed through a long incision over the hernia site and a mesh is placed after creating a plain and closed by fine suturing. 

Which technique is the best for hernia?

The reconstructive options for hernia repair are diverse and must be tailored to a given clinical condition

The best technique for hernia repair depends upon:

Patient factor, Hernia Factor, Location of hernia, Size, and complexity 

Patient comorbidities, hernia characteristics, and skin/soft tissue factors will impact the technique chosen for the repair

Technique of Hernia Surgery: 

Fundamentally, there are three different techniques for repairing a hernia with mesh. The method chosen by the surgeon typically depends on the particular condition of the patient undergoing hernia surgery. The following are the standard surgical techniques used in hernia mesh surgeries

1. The Transabdominal pre-peritoneal or TAPP Technique

In this technique, the surgeons enter the peritoneum, i.e. the thin innermost membrane of the abdominal wall. They then place the surgical mesh in the appropriate layer of the abdominal wall with a small incision, so that it does not come in contact with the internal organs.

1. The Totally Extra-peritoneal or TEP Technique

In this type of surgery, the surgeon essentially avoids the peritoneal cavity. The TEP surgery is typically more complicated to perform than the TAPP surgery, but it also involves the use of surgical mesh. Surgeons usually opt for this procedure because it results in fewer complications as compared to TAPP surgery.

1. The Intraperitoneal On-lay Mesh Technique or IPOM Technique

In this technique, the surgeon enters the peritoneal cavity to implant a mesh on the inside of the peritoneum. The implanted surgical mesh comes in contact with the intestines and the other organs. The IPOM technique became popular in the 1990s and is typically much easier and faster to perform as compared to both, TAPP and TEP.

Complex Hernia:

A complex hernia is very large or located in a difficult site such as close to the ribs or hip bones. Failed previous surgeries also make it complex. 

Hernias can be complex when it is associated with connective tissue disorders such as obesity, diabetes, smoking, steroid use, and other factors may predispose patients to primary hernia formation, 

while incisional hernias result, by definition, from the breakdown of the fascial closure. Risk factors for incisional hernia formation include patient factors, as above, as well as technical factors at the time of the index operation, such as wound infection, the technique of fascial closure, type of surgery, and choice of the incision. Once a hernia has formed, its natural history is progressive enlargement due to an increase in wall tension at the location of the hernia.

Characteristics of complex Hernia:

• Hernia defect is greater than 8cm

• Loss of abdominal domain

• Fistulas, history of mesh infection

• History of prior hernia repair, multiple failed repairs

• History of prior open surgery

• Body mass index (BMI) >35

• High-risk medical conditions including diabetes, obesity and smoking

The most important for developing complex hernia is Incisional Hernia

Incisional Hernia: Incisional Hernia occurs in people who have had prior operation. The site of incision or scar of previous surgery can cause an area of weakness, as scar tissues never as strong as native tissue and that area of weakness causes a tear in the abdominal which creates a hole. In the presence of increased intra-abdominal pressure and potential risk factors (such as smoking or obesity), the contents of the abdomen push through creating a bulge known as incisional hernia. 

Risk Factors for Incisional Hernia:

• Post Laparotomy

• Sequel of complications like burst abdomen

• Post-operative wound infection (This increases incisional hernia risk by 70%)

• Post liver or kidney transplant

• Midline bowel surgery or gynae surgery (There is a 74% risk increase compared to non-midline)

• BMI >25 Obese patients are more likely to develop an incisional hernia

• Diabetes Mellitus, Connective Tissue Disorders, or Steroid Use

• Geriatric Population

• Active Smoker

Treatment of Complex Hernia:

The treatment of complex hernias is an outstanding example for the so-called tailored approach in hernia surgery. Complex hernias are surgical challenges and their treatment requires the entire spectrum of techniques and equipment. 

The optimal technique for repair varies depending on the exact situation including nutritional status, acute physiology, and the presence of contamination, amongst other factors. 

Advanced surgical techniques of complex hernia repair: 

There are several cases where a simple conventional technique is not a viable option. To attempt an incisional hernia repair in such cases several advanced techniques and approaches have been advised.

 The most common of these is a component separation technique (CST). With time this has been advanced to component separation technique with Transversus Abdominis Muscle Release. This is the most advanced technology that offers several advantages over conventional techniques in the management of complex incisional hernias.

Component separation is an abdominal wall reconstructive technique that strategically divides the rectus and lateral abdominal wall musculofascial layers in order to achieve tension-free midline fascial approximation.

Depending on the muscle(s) divided, the techniques of component separation can be broadly categorized into :

• Anterior Component Separation

• Posterior Component Separation

Posterior component separation techniques include: 

• The Rives-Stoppa retro rectus dissection 

• Transversus abdominis release (TAR)

Some other techniques are:

e-TEP (Extended totally extraperitoneal repair)

TARM (Trans-Abdominal Retro muscular)

TAPP (Transabdominal pre‐peritoneal)

TAP (Totally extraperitoneal)

The concept of component separation technique (CST) for the treatment of very large primary and incisional abdominal wall hernias was developed because the traditional suture and mesh techniques without relaxing the musculofascial flaps lead to unfavourable results. 

1. The Rives-Stoppa

Complex hernias especially recurrent have been managed by the Rives-Stoppa technique which is an established suture-less, tension-free, and absolute method of treatment with minimal recurrence rates. 

The Rives-Stoppa repair for complex incisional hernias confers the benefits of prosthetic repair and lower recurrence rates, but decreases certain complications (fistula formation, adhesions, skin erosion, and seroma/abscess formation) by preventing direct mesh contact with the bowel.

The steps of a posterior component separation with mesh placement (Rives Stoppa) are as follows: 

• Incision and access to the abdominal cavity

• Hernia sac dissection and excision

• Posterior rectus sheath dissection and closure

• Mesh placement

• Drain placement

• Anterior rectus sheath closure

• Skin closure

1. TAR (Transversus abdominis release)

Transversus Abdominis Release (TAR) is a newly developed technique used in abdominal wall reconstruction that delivers a lasting solution to various complex incisional hernias. TAR is a novel technique of abdominal wall reconstruction which is a modification of a posterior component separation for the repair of complex incisional hernia. It is the only technique that treats complicated incisional hernias at their source.

Novitsky et al. 2012, presented a novel technique that modified the traditional surgical approach (Usually the Rives-Stoppa procedure) for patients with important abdominal wall defects. As a result, the Transversus abdominis muscle release (TAR) was proposed, showing good results in terms of recurrence, and postoperative and intraoperative complications. 

TAR technique is based on the principal goals of an abdominal wall reconstruction: restoration of abdominal wall functionality preserving autologous tissue, and reinforcement by a durable mesh with less proportion of complications. 

The procedure takes about three hours and the patient usually stays in the hospital for a day or two.

Studies show that 5% of patients treated with TAR have a recurrence, a huge improvement over those treated with open surgery. In a review by Pauli et al., the outcome for TAR showed a wound complication rate of 3.4%–31% and a recurrence rate of 1.1%–7.3%.

Indications of TAR:

1. TAR is most suited for high-risk patients, such as the morbidly obese. Historically, such patients were told to lose weight to reduce the risk of recurrence, a goal many never reached, often because they wound up in the ER with a strangulated bowel before they could lose the weight. This predicament led to the development of the new technique.

1. Other factors that indicate TAR as noble procedure include:

• Diabetes, whose accompanying microvascular problems, and effect on the blood supply interfere with the healing of the abdominal wall

• Rectus diastasis, a usually congenital but sometimes acquired issue involving the separation of the six-pack muscle

• Connective tissue diseases

• Previous hernia repair by open surgery

Types of Hernia where Transversus Abdominis Release (TAR) can provide better outcomes are:

• Large and complex ventral hernias

• Subxiphoid hernias

• Parastomal hernia

• Flank hernias

• Suprapubic hernia 

• Recurrent hernias

Advantages of the TAR procedure:

The use of the Transverse Abdominis Release (TAR) technique has demonstrated several advantages over traditional techniques when addressing complex abdominal deficiencies.

• TAR avoids large skin flaps with damage to perforator vessels, thus reducing the risk of skin necrosis, SSOs, and SSIs

• TAR allows the closure of abdominal wall defects of up to 20 cm in width

• TAR allows the implantation of very large uncoated standard alloplastic meshes in the most suitable retro muscular sublay plane.

• In most TAR cases, no mesh fixation is necessary.

• According to a recent systematic review, the SSO rates after open anterior and open TAR are comparable, but the recurrence rate after open anterior Component Separation Technique is higher compared to that of open TAR

• Posterior component separation with retro rectus mesh placement offers the advantages of low recurrence rates, low rates of wound complications such as seroma or infection, and excellent incorporation of inexpensive, uncoated mesh into the abdominal wall.

The different ways in which the TAR procedure can be done:

• Open Surgical Technique

• Laparoscopic TAR

• Robotic TAR

• e-TEP approach: e-TEP TAR

• Unilateral TAR: either Open, Laparoscopic, e-TEP, or Robotic

Precautions after TAR Surgery: 

• Avoid heavy lifting, strenuous exercise, or any activity that strains the abdomen

• Stop smoking if applicable, as this can slow healing

• Manage excess weight, as this can help reduce pressure on the abdominal wall

• Make sure to manage any existing medical conditions, such as diabetes.

1. e-TEP (Extended totally extraperitoneal repair)

The enhanced view totally extraperitoneal (e-TEP) technique which was described mainly for laparoscopic inguinal hernia repair is now a platform for the repair of ventral and incisional hernias as well. eTEP is an attractive option for selected cases because of improved outcome.

The most salient features of the eTEP technique are:

 1. Fast and easy creation of the extraperitoneal space.

 2. A large surgical field.

 3. A flexible port setup adaptable to many clinical situations.

 4. Unencumbered parietalization of the cord structures (proximal dissection of the sac and

peritoneum).

 5. Easier management of the distal sac in cases of large inguinoscrotal hernias.

 6. Improved tolerance of pneumoperitoneum, which is a common complication.

Indications for eTEP

 We use the eTEP technique to repair most cases of inguinal hernias; however, there are cases for which eTEP is especially useful.

 1. eTEP is easier to master for surgeons new to the technique. 

 2. Obese or post-bariatric patients: eTEP allows the surgeon to avoid the difficulties caused by the pannus; in addition, the subcutaneous tissue is thinner and higher in the abdomen.

 3. When the distance between the umbilicus and pubic tubercle is short.

 4. In patients with previous pelvic surgeries.

 5. Wide variety of indications: with experience, surgeons can expand the indications for eTEP for inguinal hernia repair to cases of large inguinoscrotal, sliding, or incarcerated hernias. This may require a combination with a 5 mm laparoscopic intraperitoneal approach to verify the viability of the intestine or assist in reducing the incarcerated content.

1. Laparoscopic Trans-Abdominal Retromuscular (TARM) 

TARM repair, introduced by Masurkar, is a transperitoneal low-cost procedure that could be performed with conventional instruments with an ergonomic triangulation of the ports, making intracorporeal suturing more convenient.

TARM reduces the probability of bowel injury. The working space is wider than the retro rectus space, allowing better vision, dissection, and suturing. However, this technique required an additional set of ports to create the same space on the opposite side.

A horizontal closure of the posterior rectus sheath is routinely performed in TARM, which would decrease the chances of complication. This may be attributed to the horizontal orientation of aponeurotic fibers in the posterior rectus sheath, which is thus better approximated horizontally than vertically.

For irreducible ventral hernia, TARM appeared to be safer than eTEP as the reduction of hernia contents was under vision, which was further aided by ergonomic port placement and wider working space, allowing ease in adhesiolysis. 

Laparoscopic TARM was found to be effective for repairing small- and medium-sized irreducible ventral hernias. Sublay mesh placement avoided mesh–bowel contact. 

 Myo-fascial medicalization for tension-free closure, if needed, could be achieved via posterior component separation-transversus abdominis release with the same port

The larger working space and clear anatomy provide easy understanding and reproducibility. 

Intraperitoneal composite meshes, balloon dissectors, and robotic arms were not needed. Further cost reduction could be achieved by using electrosurgical dissection instead of a harmonic scalpel. 

Loss of Domain:

Incisional hernia treatment is challenging for surgeons, especially when there is a loss of domain. This ‘‘loss of domain’’ means that the herniated viscera of the abdominal content inhabit, in a permanent way, the hernia sac, which behaves like a second abdominal cavity. Restoring the hernia sac contents to the abdominal cavity may lead to respiratory and circulatory disturbances. It can also result in abdominal compartment syndrome (ACS), which occurs when the intra-abdominal pressure (IAP) rises faster than physiological adaptations and can be fatal in severe situations

The relationship between the volume of the hernia sac versus the volume of the abdominal cavity is the best criterion for defining whether there is a loss of domain (LOD). 

LOD is defined when the volume of the sac/hernia content is greater than 25% of the volume of the abdominal cavity.

 This fundamental information allows the surgeon to consider that:

There may not be enough space to reduce all herniated contents into the abdominal cavity and still achieve a complete primary fascial closure.

The significant increase in intra-abdominal pressure, due to the reduction of a large volume of content in the abdominal cavity, can cause important ventilatory restriction due to the upward compression of the diaphragm. 

For tomographic assessment of the risk of LOD in bulky hernias, we used the method described by  Tanaka et al because it is simple to understand 

A- The largest measurement of each axis should be used, even in different tomographic sections to calculate the volume of the hernia sac, as well as the volume of the abdominal cavity.

B- To determine the abdominal volume cavity (AVC), some reference points must be used: 

The measurement of the anteroposterior axis of the abdominal cavity is determined by the line that joins the muscle groups of the healthy (anterior) wall and the line that passes through the transverse processes of the vertebra (posterior). 

The CC distance is made between the first cut showing the diaphragm and the last cut showing the tailbone. The transverse distance (T) through the parietal peritoneum on each side of the abdominal cavity.

C- To determine the hernia sac volume (HSV), 

Measurement of the limits of the parietal peritoneum of the hernia sac for the CC and T axes. For the AP axis, the distance between the anterior parietal sac peritoneum hernia to a line joins the muscle groups of the healthy wall (posterior limit).

RV = HSV/ AVC

if >25% = loss of domain

Post-operative care:

The post-surgery patient is transferred to the recovery area. The anesthetist and nursing staff closely monitor the patient till the patient’s vital and pain become stable.

Once the patient becomes stable, the patient can be shifted to the ward. In most of the cases, patients are given sips of water and if tolerated well, the patient can also be given water. 

IV lines stay in place until the patient can tolerate adequate liquids. Once the patients pass flatus, patients are allowed to take soft food, followed by a normal diet

Straining should be avoided due to constipation.

To avoid deep vein thrombosis (DVT) patients are counseled to avoid dehydration, ambulation, and stockings

Recovery after hernia surgery:

Most persons who have hernia repair surgery can resume normal activities within three weeks of the procedure. 

The abdomen will be sore during the first week following surgery. Patients who undergo complex hernia surgery in Delhi are off intravenous pain medications by day 2, allowed to go home by day 4, and no longer taking pain medication and performing at their baseline activity level 7 days after surgery. 

Short-term follow-ups are necessary to ensure no signs of recurrence or wound complications.

Why Choose Dr. Aloy Mukherjee for Hernia Surgery?

Choosing Dr. Aloy Mukherjee for hernia surgery in Delhi is a decision that brings confidence and peace of mind to patients facing the need for this critical procedure. Dr. Mukherjee is a highly respected surgeon with extensive experience in performing complex hernia surgeries. His expertise is complemented by his use of the latest surgical techniques and state-of-the-art equipment, ensuring that patients receive the most advanced care available.

Dr. Mukherjee takes a patient-centered approach to hernia surgery, which begins with a thorough consultation to discuss each patient’s specific condition and the best surgical options available for them. He is known for his compassionate care and the personalized attention he gives to every patient, addressing all their concerns and ensuring they understand every step of the process.

Our Happy Patients

Mrs. Abida Khatun suffered from a Hernia, for which she underwent a successful surgery under the special care of Dr. Aloy J Mukherjee, Sr. Consultant - Bariatrics, Laparoscopic and General Surgeon at Indraprastha Apollo Hospitals, New Delhi.

Watch Mrs. Abida Khatun sharing her experience of safe and secure surgery at Indraprastha Apollo Hospitals, Delhi.

Frequently Asked Questions

Q1. Can hernia be treated without surgery?

There is no medical or conservative management of hernia. Reducible hernia surgery may be extended temporarily, but the hernia should be operated on as soon as possible to avoid complications, because once the hernia becomes irreducible or strangulated then emergency surgery is required

Q2. What are the precautions to be taken after hernia repair surgery?

• Patients are advised to avoid lifting heavy weights are strenuous activities.

• While sneezing and coughing support should be provided.

• An abdominal binder or scrotal support should be advised for 3 months.

• Patients must seek treatment for chronic cough and straining at passing urine or stools. Any kind of straining can lead to a recurrence of hernia in the future.

Q3. How do patients prepare for hernia surgery?

• Before surgery, the surgeon will prescribe a few investigations and imaging tests.

• Blood thinner medications need to be stopped 5 days before the surgery.

• Patients can get admitted either one day before surgery or on the same morning of surgery.

• Patients are advised to stop water or food at least 6 hours before surgery.

Q4. Will the patient get a lot of pain after surgery?

The severity of pain depends upon the type of procedure, open or laparoscopic. Open surgery causes more pain as compared to laparoscopic surgery. Post-surgery analgesics can reduce the pain during a hospital stay. The patient will be able to walk within 4 to 6 hours after laparoscopic surgery.

Q5. When will the patient get discharged?

Patients can get discharged the next day of surgery, but sometimes due to complex surgery or any underlying disease condition hospital stay can increase. 

Q6. When can the patient get back to work after hernia surgery?

The patient can resume work within 7 days after surgery. Sometimes patient needs more time to resume work due to the complex nature of surgery.

Q7. Can a hernia recur even after surgery?

Hernia recurrence depends on so many factors like obesity, infections, lifestyle factors like smoking, constipation, and strenuous activities.