Medical content by Elias Tsiolis, Director Surgeon · Last updated: 11 May 2026
Large Intestine (Colon)
Conditions of the colon and appendix are very common and can range from simple, mild inflammation to more serious conditions that need urgent surgery.
At Athens Surgery every patient is treated individually, with the aim of an accurate diagnosis, safe and painless treatment and a quick return to everyday life.
The most common conditions we treat include:
- Appendicitis
- Diverticula and diverticulitis
- Inflammatory and oncological diseases of the colon
- Benign polyps and pre-cancerous lesions
Innovative Techniques in Laparoscopic and Endoscopic Surgery
Early diagnosis and the right surgical intervention, when needed, save lives and prevent serious complications.
Our team has extensive experience in both laparoscopic and endoscopic techniques that offer safety, speed and an excellent cosmetic result.
At Athens Surgery, our approach to diagnosing and treating these conditions is based on up-to-date medical knowledge, experience and minimally invasive surgery.
Director Surgeon Elias Tsiolis has extensive experience with these conditions. He introduced the laparoscopic technique at Kungälv Hospital in Sweden in 2014–2015, has performed more than 2,000 therapeutic endoscopies, including removal of polyps and pre-cancerous lesions in Sweden, and spent many years on multidisciplinary tumor boards for colorectal cancer in Sweden — a country known for the excellent functioning of multidisciplinary teams in cancer care.
Diverticulosis & Diverticulitis
Diverticulosis is a common condition of the large intestine in which small outward pouches form in the bowel wall, known as diverticula.
It is a benign condition, but when a diverticulum becomes inflamed or infected it is called diverticulitis, which can cause severe abdominal pain, fever and changes in bowel habits.
Diverticulosis is very common in people over 40, and diverticulitis is its most common complication.
Everything You Need to Know About Diverticulosis & Diverticulitis
Diverticula are small “pouches” that form in the wall of the large intestine — usually in the sigmoid and descending colon. They form when pressure inside the bowel increases because of:
- constipation,
- low fiber intake, or
- weakening of the bowel wall with age.
Causes and Risk Factors
- A diet low in fiber
- Chronic constipation
- Obesity
- A sedentary lifestyle
- Older age
- Smoking
- Hereditary predisposition
Diverticulosis (without inflammation)
At this stage the diverticula do not cause inflammation and are often discovered by chance during examinations such as a colonoscopy or CT scan.
Some patients may have:
- Mild pain or a feeling of “heaviness”, usually in the lower left abdomen
- Bloating, wind, changes in bowel habits
- Alternating diarrhea and constipation
Diagnosis
- Colonoscopy or
- CT colonography (virtual colonoscopy)
Diverticulosis does not usually require surgery, but preventive care with the right diet and follow-up.
Diverticulitis (with inflammation)
Diverticulitis occurs when a diverticulum becomes inflamed or infected. It is an acute condition that can range from mild inflammation to a serious complication.
Symptoms:
- Severe pain in the lower left abdomen
- Fever and chills
- Nausea, vomiting
- Changes in bowel habits (constipation or diarrhea)
- Tenderness or rigidity of the abdomen
Diagnosis
Diagnosis is made by:
- Clinical examination and assessment of symptoms
- Blood tests (raised white cell count, CRP)
- Abdominal CT scan — the most reliable method
Treatment
Surgical Treatment
The treatment approach depends on how severe the inflammation is.
Mild diverticulitis
- Oral antibiotics
- Light diet with gradual return to normal food
- Rest and good hydration
- Follow-up by a surgeon
- Improvement usually occurs within 2–5 days.
Severe diverticulitis
- Hospital admission for intravenous antibiotics
- Monitoring with ultrasound or CT
- Drainage of abscesses
- Surgery in case of perforation or abscess
Surgical Treatment
In cases of repeated attacks or complications such as narrowing of the colon, surgical removal of the affected part of the colon (usually sigmoid colectomy) is recommended.
- Laparoscopic sigmoid colectomy
- Small incisions
- Minimal pain
- Fast recovery
- Excellent cosmetic result
- 2–3 day hospital stay
Aftercare
- Liquids and light food for the first days
- Return to a normal diet within 1 week
- Light exercise after 10–14 days
- Return to work in 2–3 weeks
The chance of recurrence after a proper operation is minimal.
Frequently Asked Questions
Is diverticulitis dangerous?
Yes, if not treated in time it can lead to perforation, abscess or peritonitis.
Can I have diverticula without knowing it?
Yes. Many people have diverticulosis without any symptoms.
What should I avoid in my diet?
Avoid foods that cause constipation or wind (processed foods, red meat, fried food). Choose fiber, fruit and vegetables, together with good hydration.
Can fiber help?
Yes, it is the most important preventive measure. Fiber regulates bowel function and reduces pressure on the bowel wall.
When is surgery needed?
When there are repeated episodes or complications (abscess, perforation, narrowing, fistula).
How safe is the laparoscopic operation?
It is very safe, with a relatively low complication rate.
Will the diverticula come back?
Not in the removed section, but they may appear elsewhere in the bowel if lifestyle does not change.
When should I have a colonoscopy?
After the inflammation has settled (in 6–8 weeks), to rule out other conditions.
Appendicitis
Appendicitis is an acute inflammation of the appendix, a small tube-shaped section at the start of the large intestine. It is one of the most common causes of acute abdominal pain and needs prompt medical assessment, because delay can lead to rupture (perforation) and peritonitis, which is potentially dangerous.
Appendicitis can occur at any age, but it is most often seen in young adults and teenagers.
Everything You Need to Know About Appendicitis
Causes and Risk Factors
The inflammation is usually caused by a blockage of the inside of the appendix. This blockage leads to a build-up of mucus and bacteria and increased pressure, causing inflammation and infection.
Most common causes:
- Blockage by a fecalith (hardened stool)
- Enlarged lymphoid tissue
- A foreign body or parasites
- A bowel infection that spreads to the appendix
Symptoms
The typical clinical picture develops over a few hours up to two days and includes:
- Pain around the navel that moves to the lower right abdomen
- Loss of appetite, nausea, vomiting
- Low to moderate fever
- Tenderness in the lower right abdomen
- Diarrhea or constipation in some cases
The intensity and location of the pain may vary depending on the position of the appendix.
Diagnosis
Diagnosis is based on:
- Clinical examination
- Laboratory tests: raised white blood cells and inflammatory markers
- Abdominal ultrasound or CT scan for confirmation
In some cases, especially in women or older people, detailed imaging is needed to rule out other conditions (ovarian cysts, diverticulitis, etc.).
Treatment
The only definitive treatment for appendicitis is appendectomy — removal of the appendix.
Surgical Treatment
Laparoscopic appendectomy
- The most established method today:
- Three small incisions (0.5–1 cm)
- Minimal post-operative pain
- 24-hour hospital stay
- Fast recovery (return to activities in 3–7 days)
- Better cosmetic result
- In cases of perforation or abscess, antibiotics may be needed before and after the operation.
Aftercare
- Light diet for the first 1–2 days
- Light activity after 48 hours
- Return to work in 5–7 days
- Wound care according to the surgeon's instructions
- Antibiotic cover in selected cases
Full recovery is quick and without complications.
Frequently Asked Questions
Is appendicitis dangerous?
Yes, if not treated promptly it can lead to rupture and peritonitis, which is an emergency and can lead to complications.
How can I tell it is appendicitis and not just an “upset stomach”?
The pain starts around the navel and moves to the right side. It is often accompanied by fever and nausea, which does not happen with simple gastritis.
Can it go away on its own?
Usually not; it needs medical assessment and surgical treatment. Delay can lead to serious complications.
What happens if the appendix “bursts”?
If it perforates, peritonitis develops — inflammation of the whole abdominal cavity — which requires an urgent operation, usually more extensive and longer, as well as antibiotics for many days.
Is the laparoscopic operation painful?
Not particularly. The pain is minimal and easily controlled with mild painkillers.
Will there be scars?
The incisions are very small and almost invisible after a few weeks.
Can I get appendicitis again?
No, once the appendix is removed it cannot come back.
Is the operation safe?
Yes. Laparoscopic appendectomy is considered one of the safest and most standardized operations in general surgery.
When should I go to hospital?
If you have pain in the lower right abdomen that lasts more than 6 hours, together with fever or vomiting.
Can it be treated with medication alone?
Not definitively. Antibiotics can delay rupture in mild cases, but appendectomy is the only definitive solution.