Sigmoid Colon Pain: Location, and Causes.
Our content is not intended nor recommended as a substitute for medical advice by your doctor. Use for informational purposes only.
The sigmoid colon lies in the left lower part of your abdomen.
Conditions affecting the sigmoid colon will cause pain in the left lower abdomen. The pain is often dull and colicky.
The most common causes of sigmoid colon pain are chronic constipation, diverticular disease, colorectal cancer, Ulcerative colitis, and others.
Causes of sigmoid colon pain include:
- Constipation (acute and chronic).
- Diverticulosis and diverticulitis.
- Infections affecting the sigmoid colon as pseudomembranous colitis.
- Irritable bowel syndrome.
- Inflammatory bowel diseases (Crohn’s disease and Ulcerative Colitits).
- Sigmoid colon cancer, and others.
1. Constipation pain.
Constipation is defined as having less than three bowel movements per week, straining, or passage of hard stools.
The most common pattern of constipation is chronic idiopathic constipation (functional constipation) and constipation-predominant IBS (reference).
The hard stool is often stored in the sigmoid and descending colon with chronic constipation.
Distension of the sigmoid colon will cause lower left abdominal pain.
About 15% of patients with chronic idiopathic constipation complain from sigmoid colon pain (reference).
Another study found that constipation was the most frequent cause of acute abdominal pain in children seeking medical advice (reference).
Feeling sigmoid colon pain in the left lower abdomen while constipated is enough to explain the pain.
Learn More About Constipation Causes and Treatment.
Stool impaction (a complication of severe constipation).
Stool impaction is a complication of severe constipation that is often seen in elderly debilitated patients.
Fecal impaction occurs when the stool in the rectosigmoid colon hardens (like a stone). If large enough, the formed mass obstructs the rectosigmoid colon.
Symptoms of stool impaction include (reference):
- A persistent urge for defecation, but nothing comes out (the urge may be absent in elderly or comatose patients).
- False diarrhea (small amounts of liquid stool due to leakage from around the impacted mass).
- Sigmoid colon pain (in the lower left abdomen).
- Bloating, nausea, and maybe vomiting.
- Distended abdomen.
Learn more about stool impaction.
2. Diverticular disesase.
Diveticulae is sac-like protrusions that mainly affect the colon (particularly the sigmoid colon).
Diverticular disease is subdivided into:
- Diverticulosis: the presence of multiple diverticula without significant inflammation or complications.
- Diverticulitis: it occurs when the diverticula get inflamed, infected, perforated, or complicated by intestinal obstruction). Diverticulitis occurs in up to 15% of patients with diverticulosis (reference).
The illustration below shows the sac-like projections of the colon (diverticular disease).
Diverticular disease is widespread. It affects up to 45% of people, and it is more prevalent in the western world.
The incidence of diverticular disease increases with age, with the highest prevalence in people who are older than 60.
The sigmoid colon is the preferred place for diverticular disease and diverticulitis. That’s why it is a common cause of sigmoid colon pain.
- Most patients with diverticular disease have no or very few symptoms.
- The most common symptom is unexplained abdominal pain or cramps (commonly sigmoid colon pain).
- Altered bowel habits (diarrhea or constipation).
- Painless blood in the stool.
B. Acute diveritculitits.
- Sharp lower left abdominal pain (sigmoid colon pain) is the most common site of pain.
- Tenderness (pain when pressing on the sigmoid area).
- Blood in the stool.
- It may be nausea and vomiting.
See a doctor if you have sigmoid colon pain with blood in the stool. The two symptoms may indicate diverticular disease, especially if you are older.
Learn More about diverticular disease.
Some organisms are more likely to affect the large intestine (including the colon and the sigmoid colon).
Common examples include:
A. Infected divertilae (diverticulitis):
which commonly cause sigmoid colon pain. We explained the condition in detail in the above section.
B. Pseudomembranous colitis:
It is an infection caused by Clostridioides Difficile bacteria. It commonly affects the elderly or immunosuppressed individuals who take long-term antibiotics.
- The non-severe disease presents with watery diarrhea.
- Lower abdominal pain (mainly sigmoid colon pain in the lower left abdomen).
- Severe cases present with mucus and blood in the stool.
- Fever (may be high-grade).
- Sometimes, mucus and blood or blood-only stools.
C. Dysentery (bacterial and amoebic).
- Lower abdominal pain (can be left lower abdominal pain in the sigmoid area).
- Diarrhea (often very frequent, with small amounts).
- Persistent urge to defecate.
- Passage of mucus and blood in the stool.
- Fever may be present.
- Nausea and vomiting.
D. Other infections that affect the colon.
- E. coli.
- And others.
Learn More about large intestinal infections.
4. Irritable Bowel Syndorme (IBS).
Inflammatory bowel syndrome is a common functional disease of the gastrointestinal tract.
The disease is very common to the degree that it represents about 40% of the total visits to gastroenterology clinics (reference).
No organic lesion can be detected with IBS. Instead, it is a malfunction of your digestive system characterized by chronic abdominal pain with changes in bowel habits.
Until now, researchers found no apparent cause of IBS. All we know is that it affects females more than males, and it is less common to begin after 50.
- To diagnose IBS, you should have prolonged abdominal pain (at least one day per week for the past three months).
- The onset of the attack of abdominal pain is often associated with changes in bowel habits (diarrhea and/or constipation).
- Passage of mucus with stools during the attack.
- Changes in stool form (The stool becomes hard or loose during the flare-ups).
- The pain often disappears during sleep.
- The pain can be anywhere in your abdomen, including the sigmoid colon pain area.
Learn more about IBS and its pain locations.
5. Inflammatory Bowel Disease (IBD).
Inflammatory bowel disease is characterized by unexplained inflammation and ulceration of:
- The colon only (ulcerative colitis).
- The entire gastrointestinal tract (Crohn’s disease).
According to the CDC, about 1.3% of us adults (around 3 million) reported being diagnosed with IBD (reference).
Sigmoid or left colon ulcerative colitis can cause sigmoid colon pain.
symptoms of IBD:
- Persistent or recurrent diarrhea.
- Abdominal pain.
- Blood or blood and mucus coming out with or without a stool.
- Weight loss.
- Generalized fatigue.
- Fever may occur.
- Loss of appetite.
6. Colorectal cancer.
Pain is rare with colorectal cancer (CRC). Therefore, there is no need to worry and expect the worst scenario every time you experience pain.
Isolated abdominal pain (with no other symptom) is a rare presentation of colorectal cancer (CRC), affecting only 3% of the cases.
People with colorectal cancer often present with other symptoms such as changes in bowel habits, blood in stool, and loss of weight.
The symptoms of CRC and their frequency (reference):
1. Having constipation or diarrhea occurs in 75% of colon cancer patients (Unfortunately, diarrhea and constipation are also prevalent with IBS)
2. Dark or bright red blood in stool found in about 50% of colon cancer patients
3. A sense of anorectal mass in about 25%
4. Anemia and iron deficiency in about 10%
5. Isolated abdominal pain only 3.8%
Also, other general symptoms (not related to your colon) may be present like:
- Unexplained fever.
- Progressive weight loss.
- Easy fatigue and shortness of breath with mild exertion.
Other less common causes of sigmoid colon pain include:
- Food intolerance (such as lactose intolerance).
- Simple gas spasms.
- Colon polyps.
- Intestinal obstruction.
- Mesenteric vascular occlusion.
Mimics of Sigmoid colon pain:
Pain over the sigmoid colon area (the left lower abdomen) is not necessarily of a colonic origin.
Other internal organs and the abdominal wall structures can be the source of pain.
Examples of Mimics of sigmoid colon pain:
- Ureteric pain (often due to ureteric stone on the left side).
- Left ovarian cyst.
- Left ovulation pain.
- Left ovarian cancer.
- Left pelvic inflammatory disease.
- Lower left abdominal muscle strain.
- Left inguinal hernia.
- Left pelvic kidney.
- Left ectopic pregnancy (in the left fallopian tube).