Skip to main content

20th Century Cowhide Chairs

to
29
229
104
338
1
120
16
10
5
3
3
2
1
1
1
338
1
22
137
48
2
1
318
300
117
92
79
114
110
96
39
31
335
335
335
13
11
9
9
8
Sort By
Pierre Jeanneret Chair in Cowhide
Pierre Jeanneret Chair in Cowhide

Pierre Jeanneret Chair in Cowhide

By Pierre Jeanneret

Located in Los Angeles, CA

Pierre Jeanneret Chair in Cowhide.

Category

Early 20th Century Indian Chairs

Materials

Cowhide, Rosewood

19th Century Horn Chair Cowhide Western Steer.
19th Century Horn Chair Cowhide Western Steer.

19th Century Horn Chair Cowhide Western Steer.

Located in Buchanan, MI

19th Century Horn Chair Cowhide Western Steer.

Category

Early 20th Century Adirondack Office Chairs and Desk Chairs

Materials

Cowhide

Mid Century Modern Knoll Style Barcelona Chair Newly Reupholstered Cowhide
Mid Century Modern Knoll Style Barcelona Chair Newly Reupholstered Cowhide

Mid Century Modern Knoll Style Barcelona Chair Newly Reupholstered Cowhide

By Ludwig Mies van der Rohe, Knoll

Located in Chicago, IL

Vintage Mid Century Modern Mies Van Der Rohe for Knoll Barcelona Style Chair Newly Reupholstered in

Category

Mid-20th Century American Mid-Century Modern Chairs

Materials

Cowhide, Leather, Upholstery

Vintage Boho Cowhide Lounge Chair
Vintage Boho Cowhide Lounge Chair

Vintage Boho Cowhide Lounge Chair

Located in West Palm Beach, FL

in genuine brown and white cowhide! Each chair covered in natural hair-on-hide is truly one-of-a-kind

Category

Late 20th Century American Rustic Lounge Chairs

Materials

Cowhide, Upholstery, Wood

Modernist accent chair in black cowhide and ebonized oak, late 20th century
Modernist accent chair in black cowhide and ebonized oak, late 20th century

Modernist accent chair in black cowhide and ebonized oak, late 20th century

Located in View Park, CA

late 20th century or early 21st. The oak frame is reminiscent of Danish modern sensibilities, recalling

Category

21st Century and Contemporary Unknown Post-Modern Chairs

Materials

Fabric, Wood

Cowhide Leather Chesterfield Dining / Side Chair in English Style
Cowhide Leather Chesterfield Dining / Side Chair in English Style

Cowhide Leather Chesterfield Dining / Side Chair in English Style

Located in Harderwijk, NL

Offered here is this beautiful and luxurious cowhide leather Chesterfield dining or side chair in

Category

20th Century Chesterfield Chairs

Materials

Cowhide, Leather, Wood

Arne Jacobsen For Fritz Hansen Egg Chair In Brazilian Cowhide
Arne Jacobsen For Fritz Hansen Egg Chair In Brazilian Cowhide

Arne Jacobsen For Fritz Hansen Egg Chair In Brazilian Cowhide

By Arne Jacobsen, Fritz Hansen

Located in Saint Louis, US

Experience timeless design with the iconic 'Egg' chair by Arne Jacobsen for Fritz Hansen. Newly

Category

Mid-20th Century Danish Scandinavian Modern Swivel Chairs

Materials

Cowhide

Cowhide Leather Club Chair in English Style
Cowhide Leather Club Chair in English Style

Cowhide Leather Club Chair in English Style

Located in Harderwijk, NL

Offered here is this stylish and timeless brown cowhide leather club armchair in classic English

Category

20th Century Classical Roman Club Chairs

Materials

Cowhide, Leather

Mid-Century Lounge Chair in Style of Pierre Jeanneret in Cowhide, c. 1950s
Mid-Century Lounge Chair in Style of Pierre Jeanneret in Cowhide, c. 1950s

Mid-Century Lounge Chair in Style of Pierre Jeanneret in Cowhide, c. 1950s

By Pierre Jeanneret

Located in Hønefoss, 30

A beautiful Mid-Century lounge chair produced in Norway, c 1950s, in the style of Pierre Jeanneret

Category

Mid-20th Century Norwegian Mid-Century Modern Lounge Chairs

Materials

Cowhide, Beech

Set of 2 Cowhide Leather Chesterfield Chairs in Light Cognac Color
Set of 2 Cowhide Leather Chesterfield Chairs in Light Cognac Color

Set of 2 Cowhide Leather Chesterfield Chairs in Light Cognac Color

Located in Harderwijk, NL

. The chairs are crafted from high-quality cowhide leather. They are highly versatile: ideal for use at

Category

20th Century Classical Roman Chairs

Materials

Cowhide, Leather

20th Century Spanish Hair On Hide Campaign Chair
20th Century Spanish Hair On Hide Campaign Chair

20th Century Spanish Hair On Hide Campaign Chair

Located in Fort Collins, CO

places have in common? Both of these locales would accommodate this Spanish-style campaign chair. With a

Category

Mid-20th Century Spanish Colonial Chairs

Materials

Cowhide, Leather, Oak

Red Cowhide Leather English Chesterfield Wingback Chair
Red Cowhide Leather English Chesterfield Wingback Chair

Red Cowhide Leather English Chesterfield Wingback Chair

Located in Harderwijk, NL

Offered here is this classic red cowhide leather English Chesterfield wingback armchair with an

Category

20th Century Chesterfield Wingback Chairs

Materials

Cowhide, Leather

Cowhide F675 Butterfly Chair by Pierre Paulin for Artifort
Cowhide F675 Butterfly Chair by Pierre Paulin for Artifort

Cowhide F675 Butterfly Chair by Pierre Paulin for Artifort

By Artifort, Pierre Paulin

Located in Izegem, VWV

The F675 als known as the Butterfly Chair was designed by Pierre Paulin in 1963 and manufactured by

Category

Mid-20th Century Dutch Mid-Century Modern Club Chairs

Materials

Metal

Cowhide Leather Wingback Chair in Light Cognac Color
Cowhide Leather Wingback Chair in Light Cognac Color

Cowhide Leather Wingback Chair in Light Cognac Color

Located in Harderwijk, NL

character that exudes tranquility and elegance. The chair features a loose seat cushion and offers

Category

20th Century Classical Roman Wingback Chairs

Materials

Cowhide, Leather

Cowhide Leather English-Style Club Chair in Light Cognac Color
Cowhide Leather English-Style Club Chair in Light Cognac Color

Cowhide Leather English-Style Club Chair in Light Cognac Color

Located in Harderwijk, NL

Offered here is this well-preserved cowhide leather English-style club armchair in a light cognac

Category

20th Century Classical Roman Club Chairs

Materials

Cowhide, Leather

Bordeaux Red Cowhide Leather Wingback Chair in English Style
Bordeaux Red Cowhide Leather Wingback Chair in English Style

Bordeaux Red Cowhide Leather Wingback Chair in English Style

Located in Harderwijk, NL

Offered for sale is this beautiful and comfortable Bordeaux red wingback chair in English style

Category

20th Century Classical Roman Wingback Chairs

Materials

Cowhide, Leather

Cognac-Colored Cowhide Leather Wingback Chair in English Style
Cognac-Colored Cowhide Leather Wingback Chair in English Style

Cognac-Colored Cowhide Leather Wingback Chair in English Style

Located in Harderwijk, NL

Offered here is this stylish and well-maintained cognac-colored cowhide leather wingback armchair

Category

20th Century Classical Roman Wingback Chairs

Materials

Cowhide, Leather

Black Cowhide Leather English-Style Club Chair with a Timeless Design
Black Cowhide Leather English-Style Club Chair with a Timeless Design

Black Cowhide Leather English-Style Club Chair with a Timeless Design

Located in Harderwijk, NL

Offered here this stunning black cowhide leather English-style club armchair with a timeless design

Category

20th Century Classical Roman Club Chairs

Materials

Cowhide, Leather

Red classic swivel cowhide Chesterfield office chair on wheels
Red classic swivel cowhide Chesterfield office chair on wheels

Red classic swivel cowhide Chesterfield office chair on wheels

Located in Harderwijk, NL

Up for sale is this classic red, swiveling, cowhide Chesterfield office chair on casters with a

Category

20th Century Office Chairs and Desk Chairs

Materials

Cowhide, Leather

Large Dark Brown Cowhide Leather Chesterfield Wingback Chair in English Style
Large Dark Brown Cowhide Leather Chesterfield Wingback Chair in English Style

Large Dark Brown Cowhide Leather Chesterfield Wingback Chair in English Style

Located in Harderwijk, NL

Offered here this large, classic dark brown cowhide leather Chesterfield wingback chair in English

Category

20th Century Chesterfield Wingback Chairs

Materials

Cowhide, Leather

Set of 2 English-style cowhide wing chairs with a luxurious finish
Set of 2 English-style cowhide wing chairs with a luxurious finish

Set of 2 English-style cowhide wing chairs with a luxurious finish

Located in Harderwijk, NL

Up for auction is this comfortable and beautiful set of two English-style cowhide wing chairs with

Category

20th Century Wingback Chairs

Materials

Cowhide, Leather

Cowhide club chair in good condition, with rich deep colors in English style
Cowhide club chair in good condition, with rich deep colors in English style

Cowhide club chair in good condition, with rich deep colors in English style

Located in Harderwijk, NL

This wonderful cow leather club armchair is full of character and exudes dignity and luxury. It can easily be placed in almost any interior. Don't miss your chance to bring it into y...

Category

20th Century Club Chairs

Materials

Cowhide

Red Cowhide Leather Chesterfield Office Chair in English Style
Red Cowhide Leather Chesterfield Office Chair in English Style

Red Cowhide Leather Chesterfield Office Chair in English Style

Located in Harderwijk, NL

Offered here is this red cowhide leather height-adjustable Chesterfield office chair in English

Category

Late 20th Century Chesterfield Office Chairs and Desk Chairs

Materials

Cowhide, Leather

Set of 5 Cowhide Leather Chesterfield Dining Chairs in Light Cognac Color
Set of 5 Cowhide Leather Chesterfield Dining Chairs in Light Cognac Color

Set of 5 Cowhide Leather Chesterfield Dining Chairs in Light Cognac Color

Located in Harderwijk, NL

elegance. The chairs are made from high-quality cowhide leather. They are versatile in use: perfect around

Category

20th Century Chesterfield Dining Room Chairs

Materials

Cowhide, Leather

Elegant green English Chesterfield office chair made of cowhide leather
Elegant green English Chesterfield office chair made of cowhide leather

Elegant green English Chesterfield office chair made of cowhide leather

Located in Harderwijk, NL

Up for auction is this elegant green English Chesterfield office chair made of cowhide. Can you

Category

20th Century Office Chairs and Desk Chairs

Materials

Cowhide, Leather, Wood

Set of 4 cowhide leather Chesterfield dining chairs in light cognac colour
Set of 4 cowhide leather Chesterfield dining chairs in light cognac colour

Set of 4 cowhide leather Chesterfield dining chairs in light cognac colour

Located in Harderwijk, NL

This wonderful set of 4 Chesterfield chairs exudes luxury and stateliness. These chairs are made of

Category

20th Century Chesterfield Dining Room Chairs

Materials

Cowhide, Leather

Old Hickory Rocking Chair W/Leather Back & Cowhide Seat
Old Hickory Rocking Chair W/Leather Back & Cowhide Seat

Old Hickory Rocking Chair W/Leather Back & Cowhide Seat

Located in Los Angeles, CA

This signed Old Hickory rocking chair is in fine condition with a leather backing & cowhide

Category

Early 20th Century American Adirondack Rocking Chairs

Materials

Leather, Hickory

Set of 4 Minimalist Art Deco Dining Chairs in Cowhide, Netherlands, 1940s
Set of 4 Minimalist Art Deco Dining Chairs in Cowhide, Netherlands, 1940s

Set of 4 Minimalist Art Deco Dining Chairs in Cowhide, Netherlands, 1940s

Located in Echt, NL

Set of 4 cubist dining chairs in good original condition. These chairs were manufactured in The

Category

20th Century Dutch Art Deco Dining Room Chairs

Materials

Cowhide, Hide, Wood, Oak

Green classic chesterfield office chair made of cowhide leather on wheels
Green classic chesterfield office chair made of cowhide leather on wheels

Green classic chesterfield office chair made of cowhide leather on wheels

Located in Harderwijk, NL

This charming green cowhide leather and wooden office chair is a classic and timeless addition to

Category

Late 20th Century Classical Roman Office Chairs and Desk Chairs

Materials

Cowhide, Leather

Chesterfield club armchair made of cowhide leather in English style
Chesterfield club armchair made of cowhide leather in English style

Chesterfield club armchair made of cowhide leather in English style

Located in Harderwijk, NL

This very attractive cognac brown cowhide leather Chesterfield armchair can easily be placed in

Category

Late 20th Century Classical Roman Club Chairs

Materials

Cowhide, Leather

Set of 2 Black Cowhide Leather Club Armchairs in English Style
Set of 2 Black Cowhide Leather Club Armchairs in English Style

Set of 2 Black Cowhide Leather Club Armchairs in English Style

Located in Harderwijk, NL

Offered here is this beautiful set of 2 black cowhide leather club armchairs in English style with

Category

20th Century Classical Roman Club Chairs

Materials

Cowhide, Leather

Vintage Carved Curved Back Dining Chairs Newly Reupholstered In Cowhide - 4
Vintage Carved Curved Back Dining Chairs Newly Reupholstered In Cowhide - 4

Vintage Carved Curved Back Dining Chairs Newly Reupholstered In Cowhide - 4

Located in Chicago, IL

provide exceptional comfort, making them ideal for dining or as game table chairs. Mid 20th Century

Category

Mid-20th Century Unknown Mid-Century Modern Dining Room Chairs

Materials

Animal Skin

Mid Century Eames La Fonda Chairs by Herman Miller Newly Reupholstered - Pair
Mid Century Eames La Fonda Chairs by Herman Miller Newly Reupholstered - Pair

Mid Century Eames La Fonda Chairs by Herman Miller Newly Reupholstered - Pair

By Charles Eames, Herman Miller

Located in Chicago, IL

Mid Century Modern Eames La Fonda Chairs by Herman Miller Newly Reupholstered in Zebra Print Cow

Category

Mid-20th Century American Mid-Century Modern Chairs

Materials

Aluminum

Set of 6, Mid Century Cow Hide Upholstered Bentwood Chairs by Thonet, 1950s
Set of 6, Mid Century Cow Hide Upholstered Bentwood Chairs by Thonet, 1950s

Set of 6, Mid Century Cow Hide Upholstered Bentwood Chairs by Thonet, 1950s

By Thonet

Located in Basel, BS

American Made, Mid Century Thonet chairs after Eames. Stunning, very cool authentic Bruno Weil’s No.1294

Category

Mid-20th Century American Mid-Century Modern Chairs

Materials

Bentwood, Cowhide

Niels van Eijk for Droog “Cow” Chair
Niels van Eijk for Droog “Cow” Chair

Niels van Eijk for Droog “Cow” Chair

$3,150Sale Price / item|30% Off

Niels van Eijk for Droog “Cow” Chair

By Niels van Eijk, Droog

Located in Lake Worth Beach, FL

Information: Each “Cow” chair is unique, consisting of a single, untreated cowhide. Droog has collaborated

Category

Late 20th Century Dutch Post-Modern Chairs

Materials

Cowhide

MCM Lawrence Peabody Low Barrel Back Lounge Chair Newly Reupholstered
MCM Lawrence Peabody Low Barrel Back Lounge Chair Newly Reupholstered

MCM Lawrence Peabody Low Barrel Back Lounge Chair Newly Reupholstered

By Lawrence Peabody

Located in Chicago, IL

MCM Lawrence Peabody Low Barrel Back Lounge Chair Newly Reupholstered This Mid Century Modern

Category

Mid-20th Century American Mid-Century Modern Chairs

Materials

Cowhide, Wool, Upholstery, Wood

Le Corbusier Cow-Hide Chairs by Cassina, Italy, 1965 - Signed and Numbered
Le Corbusier Cow-Hide Chairs by Cassina, Italy, 1965 - Signed and Numbered

Le Corbusier Cow-Hide Chairs by Cassina, Italy, 1965 - Signed and Numbered

By Le Corbusier, Pierre Jeanneret, Charlotte Perriand Cassina

Located in Phoenix, AZ

Pair of LC/1 chairs designed by Le Corbusier, Pierre Jeanneret, Charlotte Perriand in 1928

Category

Mid-20th Century Italian Chairs

Materials

Chrome

Gerard van den Berg – “The Rock” Lounge Chair
Gerard van den Berg – “The Rock” Lounge Chair

Gerard van den Berg – “The Rock” Lounge Chair

By Gerard Van Den Berg

Located in Boom, Vlaams Gewest

An iconic Dutch design by Gerard van den Berg, the “The Rock” lounge chair stands as a true

Category

20th Century Dutch Mid-Century Modern Lounge Chairs

Materials

Cowhide

Set of Four SE-68 Chairs by Egon Eiermann
Set of Four SE-68 Chairs by Egon Eiermann

Set of Four SE-68 Chairs by Egon Eiermann

By Egon Eiermann

Located in Los Angeles, CA

Four classic designed chairs covered in black and white cow hide. Good condition. Chairs are in

Category

20th Century German Mid-Century Modern Side Chairs

Materials

Steel

Gerard Van Den Berg For Montis Lounge Chair And Ottoman Newly Reupholstered
Gerard Van Den Berg For Montis Lounge Chair And Ottoman Newly Reupholstered

Gerard Van Den Berg For Montis Lounge Chair And Ottoman Newly Reupholstered

By Gerard Van Den Berg

Located in Chicago, IL

statement of design. Circa Mid 20th Century Dimensions: Chair: H 31" W 29" D 41" SH 15.5" SD 20" AH 23

Category

Mid-20th Century Unknown Post-Modern Lounge Chairs

Materials

Cowhide

Pair of Wrought Iron French Art Deco Chairs with Zebra Print
Pair of Wrought Iron French Art Deco Chairs with Zebra Print

Pair of Wrought Iron French Art Deco Chairs with Zebra Print

Located in Los Angeles, CA

An exquisite pair of beautifully designed French Art Deco wrought iron Chairs upholstered in Zebra

Category

20th Century Art Deco Side Chairs

Materials

Wrought Iron, Iron

Cognac-colored English cow leather club chair finished with decorative nails
Cognac-colored English cow leather club chair finished with decorative nails

Cognac-colored English cow leather club chair finished with decorative nails

Located in Harderwijk, NL

This wonderful cognac-colored cow leather club armchair, with its timeless design and comfortable seat, is the perfect place to relax after a long day. It features a removable cushio...

Category

20th Century Club Chairs

Materials

Cowhide

Vintage Italian Cream Lacquer Barrel Back Occasional Chair by Tonon
Vintage Italian Cream Lacquer Barrel Back Occasional Chair by Tonon

Vintage Italian Cream Lacquer Barrel Back Occasional Chair by Tonon

By Tonon

Located in Chicago, IL

Buttercream Brazilian Cowhide with Nailhead Trim Finish We completely refurbished this Tonton style chair

Category

Late 20th Century Italian Mid-Century Modern Lounge Chairs

Materials

Cowhide, Upholstery, Lacquer

Antonio Citterio ”Timeless” Lounge Scissor Chairs for Flexform Newly Upholstered
Antonio Citterio ”Timeless” Lounge Scissor Chairs for Flexform Newly Upholstered

Antonio Citterio ”Timeless” Lounge Scissor Chairs for Flexform Newly Upholstered

By Antonio Citterio, Flexform

Located in Chicago, IL

Mid Century Modern Antonio Citterio ”Timeless” Lounge Scissor Chairs for Flexform Newly

Category

Late 20th Century American Mid-Century Modern Lounge Chairs

Materials

Chrome

Pair of Vintage Midcentury Restored Jens Risom Lounge Chairs
Pair of Vintage Midcentury Restored Jens Risom Lounge Chairs

Pair of Vintage Midcentury Restored Jens Risom Lounge Chairs

By Jens Risom

Located in Pasadena, TX

furniture and interiors. In 1939, Risom emigrated to the U.S. and in 1941 designed the first chair

Category

Mid-20th Century Danish Mid-Century Modern Lounge Chairs

Materials

Cowhide, Walnut

‘Buffalo’ Lounge Chair in Cow Hide and Steel by Kwok Hoi Chan, France 1969
‘Buffalo’ Lounge Chair in Cow Hide and Steel by Kwok Hoi Chan, France 1969

‘Buffalo’ Lounge Chair in Cow Hide and Steel by Kwok Hoi Chan, France 1969

By Steiner, Kwok Hoi Chan

Located in Echt, NL

of 20th-century design. It embodies the fusion of organic and industrial materials The chair

Category

20th Century French Mid-Century Modern Lounge Chairs

Materials

Metal, Steel

Pair Patinated Mastercraft Faux Bamboo Chairs with Pony Skin Upholstery
Pair Patinated Mastercraft Faux Bamboo Chairs with Pony Skin Upholstery

Pair Patinated Mastercraft Faux Bamboo Chairs with Pony Skin Upholstery

Located in Los Angeles, CA

A pair of heavily and beautifully patinated Faux Bamboo Chairs by Mastercraft. The chairs are

Category

Mid-20th Century Mid-Century Modern Side Chairs

Materials

Metal

  • 1
Get Updated with New Arrivals
Save "20th Century Cowhide Chairs", and we’ll notify you when there are new listings in this category.

20th Century Cowhide Chairs For Sale on 1stDibs

There is a range of 20th century cowhide chairs for sale on 1stDibs. The range of distinct 20th century cowhide chairs — often made from animal skin, cowhide and wood — can elevate any home. 20th century cowhide chairs have been made for many years, and versions that date back to the 20th Century alongside those produced as recently as the 20th Century. There are many kinds of 20th century cowhide chairs to choose from, but at 1stDibs, Mid-Century Modern, Modern and Scandinavian Modern 20th century cowhide chairs are of considerable interest. There have been many well-made 20th century cowhide chairs over the years, but those made by Pierre Jeanneret, Le Corbusier and Knoll are often thought to be among the most beautiful.

How Much are 20th Century Cowhide Chairs?

Prices for 20th century cowhide chairs start at $345 and top out at $80,588 with the average selling for $4,600.

Finding the Right Seating for You

With entire areas of our homes reserved for “sitting rooms,” the value of quality antique and vintage seating cannot be overstated.

Fortunately, the design of side chairs, armchairs and other lounge furniture — since what were, quite literally, the early perches of our ancestors — has evolved considerably.

Among the earliest standard seating furniture were stools. Egyptian stools, for example, designed for one person with no seat back, were x-shaped and typically folded to be tucked away. These rudimentary chairs informed the design of Greek and Roman stools, all of which were a long way from Sori Yanagi's Butterfly stool or Alvar Aalto's Stool 60. In the 18th century and earlier, seats with backs and armrests were largely reserved for high nobility.

The seating of today is more inclusive but the style and placement of chairs can still make a statement. Antique desk chairs and armchairs designed in the style of Louis XV, which eventually included painted furniture and were often made of rare woods, feature prominently curved legs as well as Chinese themes and varied ornaments. Much like the thrones of fairy tales and the regency, elegant lounges crafted in the Louis XV style convey wealth and prestige. In the kitchen, the dining chair placed at the head of the table is typically reserved for the head of the household or a revered guest.

Of course, with luxurious vintage or antique furnishings, every chair can seem like the best seat in the house. Whether your preference is stretching out on a plush sofa, such as the Serpentine, designed by Vladimir Kagan, or cozying up in a vintage wingback chair, there is likely to be a comfy classic or contemporary gem for you on 1stDibs.

With respect to the latest obsessions in design, cane seating has been cropping up everywhere, from sleek armchairs to lounge chairs, while bouclé fabric, a staple of modern furniture design, can be seen in mid-century modern, Scandinavian modern and Hollywood Regency furniture styles.

Admirers of the sophisticated craftsmanship and dark woods frequently associated with mid-century modern seating can find timeless furnishings in our expansive collection of lounge chairs, dining chairs and other items — whether they’re vintage editions or alluring official reproductions of iconic designs from the likes of Hans Wegner or from Charles and Ray Eames. Shop our inventory of Egg chairs, designed in 1958 by Arne Jacobsen, the Florence Knoll lounge chair and more.

No matter your style, the collection of unique chairs, sofas and other seating on 1stDibs is surely worthy of a standing ovation.

Questions About 20th Century Cowhide Chairs
  • 1stDibs ExpertApril 5, 2022
    What painting is the most important of the 20th century is largely a matter of personal opinion. Some notable works produced during the period include Paul Cézanne's Mont Sainte-Victoire, Pablo Picasso's Les Demoiselles d'Avignon, Henri Matisse's The Dance and Jackson Pollock's Lavender Mist. Shop a large selection of 20th-century paintings on 1stDibs.