biology

Internal rectal prolapse

Internal rectal prolapse 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 Internal rectal prolapse rather than just read about it. In short: Internal rectal prolapse (IRP) is medical condition involving a telescopic, funnel-shaped infolding of the wall of the rectum that occurs during defecation. The term IRP is used when the prolapsed section of rectal wall remains inside the body and is not visible outside the body.

Key takeaways

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

Reference excerpt

Internal rectal prolapse (IRP) is medical condition involving a telescopic, funnel-shaped infolding of the wall of the rectum that occurs during defecation. The term IRP is used when the prolapsed section of rectal wall remains inside the body and is not visible outside the body. IRP is a type of rectal prolapse. The other main types of rectal prolapse are external rectal prolapse (where the prolapsed segment of rectum protrudes through the anus and is visible externally) and rectal mucosal prolapse (where only the mucosal layer of the wall of the rectum prolapses). IRP may not cause any symptoms, or may cause obstructed defecation syndrome (difficulty during defecation) and/or fecal incontinence. The causes are not clear. IRP may be the first stage of a progressive condition that eventually results in external rectal prolapse. However, it is uncommon for IRP to progress to external rectal prolapse. It is possible that chronic straining during defecation (dyssynergic defecation / anismus), connective tissue disorders, and anatomic factors (e.g. loose connection of rectum to the sacrum, redundant sigmoid, deep pouch of Douglas) are involved. If IRP is causing symptoms, treatment is by various non-surgical measures such as biofeedback, or surgery. The most common surgical treatment for IRP is ventral rectopexy. IRP is often associated with other conditions such as rectocele, enterocele, or solitary rectal ulcer syndrome. IRP usually affects females who have given birth at least once, but it may sometimes affect females who have never given birth. About 10% of cases of IRP are in males. More severe forms of IRP are associated with older age.

Definitions Three main types of rectal prolapse are usually identified. These are external rectal prolapse (full thickness / complete rectal prolapse), internal rectal prolapse, and rectal mucosal prolapse. There are several different synonymous terms for IRP, and it has no universally accepted definition. Internal rectal prolapse (IRP) is a telescopic, funnel-shaped invagination (infolding) of the rectal wall that occurs during defecation. The prolapsed segment of rectal wall remains confined within the rectum or the anal canal and is not visible externally (i.e., proximal to the anus). IRP may be a circumferential infolding (involving the full circumference of the rectal wall) or unilateral infolding (involving only one side of the circumference). Usually IRP is defined as a full thickness prolapse of the rectal wall (i.e., involving all three layers). However, sometimes IRP is defined as involving the full thickness of the rectal wall or only part of it. Many synonyms for IRP include the term intussusception. When used unqualified, the term intussusception (or intestinal intussusception) refers to telescopic infolding of a section of the wall of the intestine into the portion directly in front. This is sometimes conceptualized as pulling a sock partially inside out, creating a tube within a tube. The part that moves into the other is called the intussusceptum, and the part that receives it is called the intussuscipiens. This condition usually occurs in the small intestine in children. It less commonly happens in the colon or in adults. Terms like rectal intussusception, rectoanal intussusception, internal intussusception refer to IRP, which is an entirely different medical condition from intussusception (intestinal intussusception). External rectal prolapse (also termed complete / full-thickness rectal prolapse, or procidentia) is when the prolapsed segment of rectal wall protrudes through the anus. External rectal prolapse may be visible externally while the individual is straining, whereas IRP is not visible externally and can only be detected with investigations like proctoscopy or defecography. External rectal prolapse is a full thickness, circumferential prolapse. Usually it is possible to push the prolapsed rectal wall back into the body, but sometimes it may become strangulated which may represent a medical emergency. Rectal mucosal prolapse (or simply mucosal prolapse) is when only the mucosal layer of the rectal wall or lining of the anal canal protrudes into or beyond the anal canal. The folds in the protruding segment of mucosa are orientated radially in rectal mucosal prolapse. In external rectal prolapse, the folds appear circumferential (concentric). Rectal mucosal prolapse usually involves less than 5 cm of tissue. External rectal prolapse usually involves more than 5 cm of tissue. In external rectal prolapse, there is a sulcus present between the anal sphincter and the prolapsed tissue itself. In rectal mucosal prolapse, there is no such sulcus. Another term, rectal internal mucosal prolapse (RIMP, or sometimes "internal mucosal rectal prolapse"), is sometimes used. It is not clear if this term refers to IRP, rectal mucosal prolapse, or a mucosal prolapse which does not protrude externally. Mucosal prolapse has been defined as infolding of less than 3 mm of the thickness of the rectal wall. If the thickness of the prolapsed segment is more than 3 mm, the term intussusception is used.

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Internal rectal prolapse

Start with the simplest possible case. Write down what Internal rectal prolapse 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 Internal rectal prolapse 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 Internal rectal prolapse 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 Internal rectal prolapse

In research: Internal rectal prolapse 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 Internal rectal prolapse 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: Internal rectal prolapse is common in secondary-school and first-year university syllabi. It links to neighbouring topics Colorectal surgery, Rectal diseases, so understanding it makes those chapters shorter.
In everyday life: Look for Internal rectal prolapse 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Internal rectal prolapse” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Internal rectal prolapse in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Internal rectal prolapse 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 Internal rectal prolapse out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Internal rectal prolapse in simple terms?

Why does Internal rectal prolapse 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 Internal rectal prolapse?

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 Internal rectal prolapse.