biology

Sigmoidocele

Sigmoidocele is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Sigmoidocele rather than just read about it. In short: Sigmoidocele (also known as pouch of Douglas descent) is a medical condition in which a herniation of peritoneum containing loops of redundant sigmoid colon descends (prolapses) into the rectouterine pouch (in females), between the rectum and the vagina. This can obstruct the rectum and cause obstructed defecation syndrome.

Key takeaways

Sigmoidocele belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Sigmoidocele to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Sigmoidocele from memory before moving on to harder problems.

Reference excerpt

Sigmoidocele (also known as pouch of Douglas descent) is a medical condition in which a herniation of peritoneum containing loops of redundant sigmoid colon descends (prolapses) into the rectouterine pouch (in females), between the rectum and the vagina. This can obstruct the rectum and cause obstructed defecation syndrome.

Classification Sigmoidocele may be internal if it is only detectable on defecography, or external if it detectable without imaging and associated with a rectocele or rectal prolapse. It is a type of posterior compartment prolapse. Sigmoidocele may be classified according to size relative to the pubococcygeal line.

Small: less than 3 cm between pubococcygeal line and the most inferior (lowest) point of the hernial sac. Moderate: 3–6 cm pubococcygeal line and the most inferior point of the sac. Large: more than 6 cm pubococcygeal line and the most inferior point of the sac. The severity of sigmoidocele can be described with reference to the position of the lowest loop of the sigmoid relative to lines drawn on defecography:

First-degree sigmoidocele: above the pubococcygeal line. Second-degree sigmoidocele: below the pubococcygeal line but above the ischiococcygeal line. Third-degree sigmoidocele: below the ischiococcygeal line.

Signs and symptoms Sigmoidocele may not cause any symptoms.

Obstructed defecation syndrome. It has been suggested that a sigmoidocele does not cause obstruction, but rather is a compensatory mechanism which increases rectal pressure and helps evacuation in the presence of excessive perineal descent. Incomplete evacuation of rectal contents. Bulge in posterior (back) wall of vagina.

Causes The phenomenon is caused by a weak section of fascial supports of the vagina (the uterosacral cardinal ligament complex and rectal vaginal septum), which allows a section of peritoneum containing the sigmoid colon to prolapse out of normal position and descend between the rectum and the vagina. The mesentery of the sigmoid colon (the structure which attaches the colon to the abdominal wall) is termed the mesosigmoid. This structure is very flexible, which means that the sigmoid colon is very mobile and may change position. During defecation it may be pushed down, eventually causing sigmoidocele. Sigmoidocele may be associated with descending perineum syndrome.

Diagnosis It is not possible to differentiate between a rectocele and a sigmoidocele on vaginal examination. Defecating proctography will demonstrate a sigmoidocele during straining.

Treatment Surgery is considered if there is a significant hernia combined with symptoms of obstructed defecation. Laparoscopic ventral mesh rectopexy has been used to correct sigmoidocele. This procedure involves inserting a mesh between the rectum and the vagina. The mesh is suspended from the sacral promontory without tension. This acts to support the recto-vaginal septum and elevate a deep pouch of Douglas. If there is prolapse of the middle compartment, sacrocolpopexy may be carried out to surgically correct all pelvic prolapse problems in the same procedure. Other treatment options are anterior resection, sigmoidopexy with rectocele repair, or sigmoidectomy.

Epidemiology Sigmoidocele normally occurs in females, and is uncommon. Sigmoidocele is detected about 4-5% of the time when defecography is carried out.

Notes

References

Worked examples

Example 1 — a first encounter with Sigmoidocele

Start with the simplest possible case. Write down what Sigmoidocele claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Sigmoidocele before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Sigmoidocele ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Sigmoidocele

In research: Sigmoidocele appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Sigmoidocele in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Sigmoidocele is common in secondary-school and first-year university syllabi. It links to neighbouring topics Colorectal surgery, Gynaecology, Noninflammatory disorders of female genital tract, so understanding it makes those chapters shorter.
In everyday life: Look for Sigmoidocele outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Sigmoidocele in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Sigmoidocele means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Sigmoidocele out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Sigmoidocele in simple terms?

Why does Sigmoidocele matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Sigmoidocele?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Sigmoidocele.