Last Updated on October 30, 2025 by Bilal Hasdemir
The sigmoid colon is a key part of the large intestine. It’s found in the lower part of the abdomen. It curves like an S between the descending colon and the rectum, near the pelvis. Knowing where it is is key for spotting and treating colon cancer and other problems.Discover the sigmoid colon location and learn how its position may relate to colon cancer and tumors.
The large intestine looks like an upside-down U in the belly. It starts in the lower right corner, goes up, then across from right to left before going down again. The sigmoid part is on the bottom left, joining the rectum.
Liv Hospital focuses on the patient, making it vital to understand this area. Tumors and cancers here can be deadly if caught late.
The sigmoid colon is in the lower belly and is shaped like an S. It’s key to our digestive health. It’s a big part of the large intestine and plays a big role in digestion.
The sigmoid colon’s S shape helps it work well in digestion. This shape lets it hold onto feces until they’re ready to come out. It’s about 35-40 cm long and sits in the pelvic area, linking the descending colon to the rectum.
The sigmoid colon is important for absorbing water and handling waste. It takes water and salts from the waste, making it thicker. This helps keep bowel movements regular and prevents diarrhea.
Experts says, “The sigmoid colon is a key part of the colon. Problems with it can cause big issues with digestion.”
“The sigmoid colon is a critical part of the colon, and its dysfunction can lead to significant gastrointestinal issues.”
It also plays a big part in waste processing. It holds onto waste until it’s time to go. The sigmoid colon’s muscles work together to push waste towards the rectum.
| Function | Description |
| Water Absorption | Absorbs water and electrolytes from fecal material |
| Waste Storage | Stores feces until they are eliminated |
| Bowel Movement Regulation | Regulates bowel movements through muscular contractions |
Colon cancer often hits older people but can happen at any age. It starts with small cell clumps called polyps in the colon. Most polyps aren’t cancerous, but some can turn into cancer. Knowing about the sigmoid colon helps us see its importance for health and why we should prevent colon cancer.
Knowing where the sigmoid colon is is key for diagnosing and treating problems. It’s a big part of the large intestine and helps a lot with digestion.
The sigmoid colon is in the lower abdominal cavity and curves like an S. This shape is important for its job in water absorption and waste processing. It’s found on the bottom left side of the abdomen.
The sigmoid colon links the descending colon and the rectum. It gets food from the descending colon and makes it ready for the rectum. The rectum then stores it until it’s time to go.
The sigmoid colon is close to other pelvic organs. This is why it’s important to look at it when diagnosing and treating. Problems here can affect nearby organs too.
To sum up, the sigmoid colon’s exact spot in the lower abdomen is vital. Its role in connecting the descending colon and rectum and its closeness to other organs highlight its importance. It’s key for digestion and can be involved in some health issues.
Sigmoid colon cancer is a big worry in the United States. It’s the third most common cancer, with over 153,000 new cases in 2023. This data comes from the Surveillance, Epidemiology, and End Results (SEER) database.
The rates of sigmoid colon cancer differ among different groups. Most cases happen in people over 50. The rates also change based on ethnicity and where you live.
Let’s look at how rates change with age and ethnicity. Below is a table showing the rates per 100,000 people for different groups.
| Age Group | Incidence Rate (per 100,000) | Ethnic Group |
| 50-59 | 45.6 | Non-Hispanic Whites |
| 60-69 | 65.3 | African Americans |
| 70+ | 85.2 | Hispanics |
Sigmoid colon cancer often happens on the left side of the colon. This includes the descending colon and sigmoid colon. The left side is more common for tumors, affecting how we screen and diagnose.
Looking at sigmoid colon cancer compared to other areas helps us understand it better. While it’s common, other spots like the rectum and ascending colon also have a lot of cases. This comparison helps us tailor treatments.
For example, cancers in the descending colon can spread to the sigmoid colon. This shows we need to screen and diagnose thoroughly, considering how close these areas are.
Knowing the types of cancers in the sigmoid colon is key for good treatment. The sigmoid colon, a part of the large intestine, faces different cancers. Adenocarcinoma is the most common type.
Adenocarcinoma makes up over 90% of cancers in the sigmoid colon. It starts in glandular cells lining the colon. This high rate makes early screening and detection very important.
Adenocarcinoma’s dominance shapes treatment plans. Knowing its traits helps in creating specific therapies.
Adenocarcinoma is the most common, but other cancers can also occur. These include neuroendocrine tumors, gastrointestinal stromal tumors (GISTs), and lymphomas. Though rarer, they need correct diagnosis and treatment.
Neuroendocrine tumors come from neuroendocrine cells and can be aggressive. GISTs are rare, coming from the gastrointestinal tract’s stromal cells. Lymphomas are cancers of the immune system that can show up in the sigmoid colon.
It’s vital to tell benign from malignant tumors in the sigmoid colon. Benign tumors, like adenomas, are not cancerous. They don’t spread or invade tissues. Malignant tumors, on the other hand, are cancerous, can spread, and invade tissues.
Knowing the difference is key for treatment. Benign tumors might not need aggressive treatment. But malignant tumors need quick and often complex treatments.
It’s important to know the warning signs of sigmoid tumors early. This can lead to better treatment. Sigmoid colon cancer and other tumors in this area have specific symptoms.
One key sign of sigmoid tumors is changes in bowel habits. You might notice persistent diarrhea or constipation, or changes in stool consistency. These signs can point to a tumor or other bowel problems.
It’s vital to watch for these changes. Even small changes should be reported to a doctor. This can help catch problems early.
Blood in the stool is a big warning sign. It can be visible or only found through tests. Rectal bleeding is a common symptom of sigmoid colon cancer.
If you see blood in your stool, see a doctor right away. They can figure out the cause and suggest tests.
Pain can also signal sigmoid tumors. Abdominal pain or cramping that doesn’t go away can be a sign. Feeling like you haven’t fully emptied your bowels or a feeling of fullness in the rectum can also happen.
Other signs include unexplained weight loss, fatigue, or feeling generally unwell. While these can mean many things, they might point to a tumor if seen with other symptoms.
Knowing these signs can help find tumors early. This can lead to better treatment chances.
The risk of sigmoid colon cancer comes from both things we can’t control and things we can. Knowing these factors helps in preventing and catching the disease early.
Genetics are a big deal in sigmoid colon cancer. If your family has a history of colorectal cancer, you’re at higher risk. Syndromes like Lynch and FAP also raise your risk a lot.
For example, people with Lynch syndrome face a big risk of colorectal cancer. Some studies say up to a 70% chance for those with certain gene mutations.
What you eat and how you live can also affect your risk. Eating a lot of red meat and processed foods, and not enough fiber, can be bad. But eating more fruits, veggies, and whole grains can help.
Being active, not being overweight, and not smoking can also lower your risk. Drinking too much alcohol might increase it.
Some health issues can up your risk of sigmoid colon cancer. Diseases like ulcerative colitis and Crohn’s can increase it, mainly if you’ve had them for a long time.
Type 2 diabetes is also linked to a higher risk of colorectal cancer. The exact reasons aren’t clear, but insulin resistance and inflammation are thought to be involved.
| Risk Factor | Description | Impact on Risk |
| Age | Risk increases with age, specially after 50 | High |
| Family History | First-degree relatives with colorectal cancer | High |
| Genetic Syndromes | Lynch syndrome, FAP | Very High |
| Diet | High in red/processed meat, low in fiber | Moderate |
| Lifestyle | Physical inactivity, obesity, smoking | Moderate to High |
| Medical Conditions | IBD, Type 2 diabetes | Moderate to High |
Knowing these risk factors helps you take steps to lower your chance of sigmoid colon cancer. You can eat better, move more, and avoid smoking.
It’s important to know how to diagnose sigmoid masses early. This helps in treating sigmoid colon cancer quickly. Doctors use many methods, from first checks to detailed scans and biopsies.
People should start screening for sigmoid colon cancer at 45, as guidelines suggest. Colonoscopy is the best way to find and remove polyps early. Other tests like fecal occult blood tests (FOBT) and CT colonography also help find problems.
Regular checks are key to finding sigmoid masses early. This makes treatment more effective. The right test depends on the patient’s health, what they prefer, and what’s available.
When a mass is thought of, doctors use detailed scans to learn more. Computed Tomography (CT) scans and Magnetic Resonance Imaging (MRI) show how big the tumor is and if it has spread. This helps figure out the best treatment.
These scans also help plan surgery. They show where the tumor is and how it relates to other parts of the body.
A biopsy and pathological examination confirm a mass diagnosis. During a colonoscopy, a sample is taken and checked for cancer. Knowing the cancer type and how aggressive it is helps decide treatment.
Early detection and diagnosis are key to better outcomes for sigmoid colon cancer patients. By using these diagnostic tools, doctors can provide the right care on time.
Treating sigmoid colon cancer needs a detailed plan. This plan often mixes surgery and other treatments. The right treatment depends on the cancer’s stage, the patient’s health, and more.
Surgery is key for treating sigmoid colon cancer that can be removed. The goal is to take out the cancer and some nearby tissue and lymph nodes.
Surgical methods can be open surgery or laparoscopic surgery. The choice depends on the cancer’s stage and the patient’s health.
Adjuvant treatments help after surgery to get rid of any cancer left behind. Chemotherapy is often used for stages II and III.
In some cases, radiation therapy is used. It can be before surgery to make the tumor smaller or after to kill any cancer cells left.
“Adjuvant chemotherapy has been shown to improve survival rates in patients with stage III colon cancer.”
New treatments like targeted therapies and immunotherapy are being used. They aim at specific cancer cell traits or boost the immune system’s fight against cancer.
| Treatment Modality | Description | Indications |
| Surgery | Removal of cancerous portion of colon | Resectable sigmoid colon cancer |
| Chemotherapy | Use of drugs to kill cancer cells | Stages II and III, metastatic disease |
| Radiation Therapy | Use of radiation to kill cancer cells | Preoperative or postoperative, locally advanced disease |
Using these treatments together helps doctors create good plans for patients with sigmoid colon cancer. This improves their chances of recovery and quality of life.
The outlook for sigmoid colon cancer patients depends on several key factors. The stage at diagnosis is a big one. Knowing these factors helps both patients and doctors make better treatment plans.
The stage of sigmoid colon cancer is the biggest factor in how well a patient will do. Staging shows how far the cancer has spread. It also tells us if more treatment is needed. Here’s how staging affects survival rates:
| Cancer Stage | 5-Year Survival Rate |
| Stage I | 93% |
| Stage II | 82% |
| Stage III | 60% |
| Stage IV | 14% |
Early detection is key to better survival rates. It lets doctors catch cancer early, before it gets worse.
Finding sigmoid colon cancer early is vital. Tests like colonoscopy can spot cancer early or stop it by removing polyps. People over 45 or with a family history of colon cancer should get screened regularly.
How well a patient does after treatment is very important. Thanks to new treatments, outcomes have gotten much better. A patient’s survival and happiness after treatment depend a lot on their quality of life.
Things that affect quality of life include the cancer stage, treatment type, and overall health. Getting care from many doctors helps with physical, emotional, and social needs. This is key for a better life after treatment.
To lower the risk of sigmoid colon cancer, it’s important to make lifestyle changes and follow screening guidelines. By doing so, people can greatly reduce their risk of getting this disease.
Choosing a healthy lifestyle is key to preventing sigmoid colon cancer. Eating a diet full of fruits, vegetables, and whole grains is essential. Also, staying active is important.
A healthy diet should be high in fiber and low in processed meats and red meat. These foods increase the risk of colon cancer.
Regular exercise helps keep a healthy weight and lowers cancer risk. It improves insulin sensitivity and reduces inflammation, which are good for preventing colon cancer.
“A healthy lifestyle is the cornerstone of colon cancer prevention. By focusing on diet, exercise, and maintaining a healthy weight, individuals can significantly reduce their risk.”
Screening for colon cancer should start at age 45 for those with average risk. Screening tests can find cancer early and remove precancerous polyps.
The right screening test depends on personal preference and medical history. Options include colonoscopy, fecal occult blood tests (FOBT), and stool DNA tests. Colonoscopy is the best because it can diagnose and remove polyps at the same time.
People with a family history of colon cancer, certain genetic syndromes, or inflammatory bowel disease are at higher risk. For high-risk individuals, screening may start earlier and happen more often.
It’s vital for those at higher risk to talk to their doctor about the best screening schedule. Genetic counseling might also be suggested for those with a strong family history or known genetic mutations.
Knowing where the sigmoid colon is and its role in digestion is key to staying healthy. Recognizing the risks of sigmoid colon cancer and taking steps to prevent it can lower your risk. This is important for your overall health.
Early detection and treatment are vital for beating sigmoid colon cancer. Screening for colon cancer can spot problems early. This makes treatment more likely to work. By focusing on sigmoid colon health, you can lower your risk and feel better overall.
Managing sigmoid colon health means preventing problems, finding issues early, and treating them. Being informed and taking action can help you avoid sigmoid colon cancer. This keeps your digestive system working well.
The sigmoid colon is in the lower belly. It’s shaped like an S and connects the descending colon to the rectum. It’s near the pelvis.
The sigmoid colon helps absorb water. It also moves and stores feces. It’s key for getting rid of waste from the body.
Risk factors include genetics, family history, diet, and lifestyle. Certain medical conditions also play a role.
Signs include changes in bowel habits, blood in stool, and pain. These are warning signs of tumors.
Doctors use screening, imaging, and biopsies to diagnose. A biopsy confirms the cancer type.
Treatments include surgery, chemotherapy, and radiation. Targeted treatments and immunotherapy are also options.
The prognosis depends on the cancer stage. Early detection is key to better survival chances.
Prevention involves a healthy diet and exercise. Regular screenings are also important, based on age.
Benign tumors are not cancerous. Malignant tumors are cancerous and can spread.
Adenocarcinoma is the main cancer type in the sigmoid colon. It starts in glandular cells lining the colon.
The sigmoid colon is close to other pelvic organs. This is important for diagnosis and treatment.
Khalil, H. M., et al. (2021). Biliary leakage following cholecystectomy: A prospective population study. Journal of Research in Medical and Dental Science, 9(5), 289-296. Retrieved from https://www.jrmds.in/articles/biliary-leakage-following-cholecystectomy-a-prospective-population-study-84919.html