OVERVIEW

We are a specialty pharmaceutical company dedicated to acquiring, developing and commercializing prescription drugs and medical devices used in the treatment of a variety of gastrointestinal disorders, which are those affecting the digestive tract. Our strategy is to:

• identify and acquire rights to products that we believe have potential for near-term regulatory approval or are already approved;

• apply our regulatory, product development, and sales and marketing expertise to commercialize these products; and

• market our products through our approximately 335-member specialty sales and marketing team primarily focused on high-prescribing U.S. physicians in the following specialties: gastroenterologists, who are doctors who specialize in gastrointestinal disorders; hepatologists, who are doctors who specialize in liver disease; and colorectal surgeons, who are doctors who specialize in disorders of the colon and rectum.

Our current products demonstrate our ability to execute this strategy. As of December 31, 2012, our products were:

• XIFAXAN®(rifaximin) Tablets 200 mg, indicated for travelers' diarrhea;

• XIFAXAN®550mg (rifaximin) Tablets 550 mg, indicated for overt hepatic encephalopathy, or HE;

• MOVIPREP® (PEG 3350, Sodium Sulfate, Sodium Chloride, Potassium Chloride, Sodium Ascorbate and Ascorbic Acid for Oral Solution), indicated for cleansing of the colon as a preparation for colonoscopy in adults 18 years of age or older;

• APRISO™ (mesalamine) extended-release capsules, indicated for the maintenance of remission of ulcerative colitis;

• RELISTOR®(methylnaltrexone bromide) subcutaneous injection (SI) indicated for the treatment of opioid-induced constipation (OIC) in patients with advanced illness who are receiving palliative care, when response to laxative therapy has not been sufficient, which we began promoting in the second quarter of 2011;

• OSMOPREP™ (sodium phosphate monobasic monohydrate, USP and sodium phosphate dibasic anhydrous, USP) Tablets, indicated for cleansing of the colon as a preparation for colonoscopy in adults 18 years of age or older;

• SOLESTA®, a biocompatible tissue-bulking agent indicated for the treatment of fecal incontinence, acquired in our purchase of Oceana in December 2011;

• DEFLUX®, a biocompatible tissue-bulking agent indicated for the treatment of vesicoureteral reflux (VUR), acquired in in our purchase of Oceana in December 2011;

• FULYZAQ™, (crofelemer) delayed-release tablets, indicated for the symptomatic relief of non-infectious diarrhea in adult patients with HIV/AIDS on anti-retroviral therapy, which the FDA approved on December 31, 2012;

• GIAZO™, (balsalazide disodium) tablets, indicated for the treatment of mildly to moderately active ulcerative colitis in male patients 18 years of age and older;

• METOZOLV™ ODT (metoclopramide hydrochloride) 5mg and 10mg orally disintegrating tablets, indicated for short-term (4 to 12 weeks) use in adults for treatment of refractory GERD, which is symptomatic, documented gastroesophageal reflux disease that fails to respond to conventional therapy, and for relief of symptoms of acute and recurrent diabetic gastroparesis;

• AZASAN®Azathioprine Tablets, USP, 75mg and 100 mg, indicated as an adjunct for the prevention of rejection in renal homotransplantations and to reduce signs and symptoms of severe active rheumatoid arthritis;

• ANUSOL-HC®2.5% (Hydrocortisone Cream, USP), ANUSOL-HC® 25 mg Suppository (Hydrocortisone Acetate), indicated for the relief of the inflammatory and pruritic manifestations of corticosteroid-responsive dermatoses;

• PEPCID®(famotidine) for Oral Suspension, indicated for the short-term treatment of gastroesophageal reflux disease (GERD), active duodenal ulcer, active benign gastric ulcer, erosive esophagitis due to GERD, and peptic ulcer disease;

• DIURIL®(Chlorothiazide), indicated for the treatment of hypertension and also as adjunctive therapy in edema associated with congestive heart failure, cirrhosis of the liver, corticosteroid and estrogen therapy, and kidney disease; and

• COLAZAL®(balsalazide disodium) Capsules 750 mg, indicated for the treatment of mildly to moderately active ulcerative colitis (UC) in patients 5 years of age and older.

We generate revenue primarily by selling our products to pharmaceutical wholesalers. These direct customers resell and distribute our products to and through pharmacies to patients who have had our products prescribed by doctors. We currently market our products, and intend to market future products, if approved by the FDA, to U.S. gastroenterologists, hepatologists, colorectal surgeons and other physicians through our own direct sales force. In December 2000, we established our own field sales force to market Colazal in the United States. As of December 31, 2012, this sales force had approximately 235 sales representatives in the field marketing our approved products. Although the creation of an independent sales organization involved substantial costs, we believe that the financial returns from our direct product sales have been and will continue to be more favorable to us than those from the indirect sale of products through marketing partners. We generally enter into distribution or licensing relationships outside the United States and in certain markets in the U.S. where a larger sales organization is appropriate. As a result of our acquisition of Oceana Therapeutics, Inc. in December 2011, we have approximately ten sales representatives based in Europe who sell Solesta and Deflux there. We also sell Deflux through distributors in approximately 20 countries outside the United States and Europe. As of December 31, 2012, our sales and marketing staff, including our sales representatives, consisted of approximately 335 people.

Because demand for our products originates with doctors, our sales force calls on high-prescribing specialists, primarily gastroenterologists, hepatologists and colorectal surgeons, and we monitor new and total prescriptions for our products as key performance indicators for our business. Prescriptions result in our products being used by patients, requiring our direct customers to purchase more products to replenish their inventory. However, our revenue might fluctuate from quarter to quarter due to other factors, such as increased buying by wholesalers in anticipation of a price increase or because of the introduction of new products. Revenue could be less than anticipated in subsequent quarters as wholesalers' increased inventory is consumed.

Our primary product candidates currently under development and their status are as follows:

          Compound                     Indication                       Status
Rifaximin                        Irritable bowel          Supplemental New Drug Application,
                                 syndrome, or IBS         or sNDA, submitted June 7, 2010;
                                                          Complete Response Letter, or CRL,
                                                          received on March 7,
                                                          2011; FDA meeting held on June 20,
                                                          2011; Advisory Committee held on
                                                          November 16, 2011; currently in
                                                          Phase 3 retreatment study

Methylnaltrexone bromide oral    Opioid induced           Phase 3
                                 constipation in
                                 patients with chronic
                                 non-malignant pain;
                                 oral

Budesonide foam                  Ulcerative proctitis     Phase 3

Rifaximin EIR                    Crohn's disease          Phase 2

CRITICAL ACCOUNTING POLICIES

General

Our discussion and analysis of our financial condition and results of operations are based upon our consolidated financial statements, which have been prepared in accordance with accounting principles generally accepted in the United States of America. The preparation of these financial statements requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. On an on-going basis, we evaluate our estimates, including those related to sales of our products, bad debts, inventories, investments, intangible assets and legal issues. We base our estimates on historical experience and on various other assumptions that we believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results might differ materially from these estimates under different assumptions or conditions.

Methodologies used and assumptions selected by management in making these estimates, as well as the related disclosures, have been reviewed by and discussed with the Audit Committee of our Board of Directors.

We believe the following critical accounting policies affect our more significant judgments and estimates used in the preparation of our consolidated financial statements.

Revenue Recognition

We recognize revenue from sales transactions where the buyer has the right to return the product at the time of sale only if (1) our price to the buyer is substantially fixed or determinable at the date of sale, (2) the buyer has paid us, or the buyer is obligated to pay us and the obligation is not contingent on resale of the product, (3) the buyer's obligation to us would not be changed in the event of theft or physical destruction or damage of the product, (4) the buyer acquiring the product for resale has economic substance apart from any provided by us, (5) we do not have significant obligations for future performance to directly bring about resale of the product by the buyer, and
(6) the amount of future returns can be reasonably estimated. We recognize revenues for product sales at the time title and risk of loss are transferred to the customer, which is generally at the time products are shipped. Our net product revenue represents our total revenues less allowances for customer credits, including estimated discounts, rebates, chargebacks, and product returns.

We establish allowances for estimated rebates, chargebacks and product returns based on numerous quantitative and qualitative factors, including:

• the number of and specific contractual terms of agreements with customers;

• estimated levels of inventory in the distribution channel;

• historical rebates, chargebacks and returns of products;

• direct communication with customers;

• anticipated introduction of competitive products or generics;

• anticipated pricing strategy changes by us and/or our competitors;

• analysis of prescription data gathered by a third-party prescription data provider;

• the impact of changes in state and federal regulations; and

• estimated remaining shelf life of products.

In our analyses, we use prescription data purchased from a third-party data provider to develop estimates of historical inventory channel pull-through. We utilize an internal analysis to compare historical net product shipments to estimated historical prescriptions written. Based on that analysis, we develop an estimate of the quantity of product in the channel that might be subject to various rebate, chargeback and product return exposures. At least quarterly for each product line, we prepare an internal estimate of ending inventory units in the distribution channel by adding

estimated inventory in the channel at the beginning of the period, plus net product shipments for the period, less estimated prescriptions written for the period. Based on that analysis, we develop an estimate of the quantity of product in the channel that might be subject to various rebate, chargeback and product return exposures. This is done for each product line by applying a rate of historical activity for rebates, chargebacks and product returns, adjusted for relevant quantitative and qualitative factors discussed above, to the potential exposed product estimated to be in the distribution channel. Internal forecasts that are utilized to calculate the estimated number of months in the channel are regularly adjusted based on input from members of our sales, marketing and operations groups. The adjusted forecasts take into account numerous factors including, but not limited to, new product introductions, direct communication with customers and potential product expiry issues. Adjustments to estimates are recorded in the period when significant events or changes in trends are identified.

Consistent with industry practice, we periodically offer promotional discounts to our existing customers. These discounts are calculated as a percentage of the current published list price and are treated as off-invoice allowances. Accordingly, we record the discounts as a reduction of revenue in the period that we offer the program. In addition to promotional discounts, at the time that we implement a price increase, we generally offer our existing customers an opportunity to purchase a limited quantity of product at the previous list price. Shipments resulting from these programs generally are not in excess of ordinary levels, therefore, we recognize the related revenue upon shipment and include the shipments in estimating our various product related allowances. In the event we determine that these shipments represent purchases of inventory in excess of ordinary levels for a given wholesaler, the potential impact on product returns exposure would be specifically evaluated and reflected as a reduction in revenue at the time of such shipments.

Allowances for estimated rebates, chargebacks and promotional programs were $103.8 million and $69.2 million as of December 31, 2012 and 2011, respectively. These allowances reflect an estimate of our liability for items such as rebates due to various governmental organizations under the Medicare/Medicaid regulations, rebates due to managed care organizations under specific contracts and chargebacks due to various organizations purchasing certain of our products through federal contracts and/or group purchasing agreements. We estimate our liability for rebates and chargebacks at each reporting period based on a methodology of applying the relevant quantitative and qualitative assumptions discussed above. Due to the subjectivity of our accrual estimates for rebates and chargebacks, we prepare various sensitivity analyses to ensure our final estimate is within a reasonable range as well as review prior period activity to ensure that our methodology is still reasonable. Had a change in one or more variables in the analyses (utilization rates, contract modifications, etc.) resulted in an additional percentage point change in the trailing average of estimated chargeback and rebate activity for the year ended December 31, 2012, we would have recorded an adjustment to revenues of approximately $9.3 million, or 1.3%, for the year.

Allowances for product returns were $36.4 million and $28.7 million as of December 31, 2012 and 2011, respectively. These allowances reflect an estimate of our liability for product that may be returned by the original purchaser in accordance with our stated return policy. We estimate our liability for product returns at each reporting period based on historical return rates, the estimated inventory in the channel, and the other factors discussed above. Due to the subjectivity of our accrual estimates for product returns, we prepare various sensitivity analyses as well as review prior period activity to ensure that our methodology is still reasonable.

For the years ended December 31, 2012, 2011 and 2010, our absolute exposure for rebates, chargebacks and product returns grew primarily as a result of increased sales of our existing products, the approval of new products and the acquisition of products. Accordingly, reductions to revenue and corresponding increases to allowance accounts have likewise increased. The estimated exposure to these revenue-reducing items as a percentage of gross product revenue in the years ended December 31, 2012, 2011 and 2010 was 15.7%, 14.6% and 14.9% for rebates, chargebacks and discounts and was 2.3%, 3.9% and 2.9% for product returns, respectively.

During the second quarter of 2010 we recognized product revenue related to initial shipments to wholesalers of Xifaxan 550mg, which the FDA approved on March 24, 2010 for reduction in risk of overt hepatic encephalopathy, or HE, recurrence in patients 18 years of age or older, and we launched to physicians in May 2010. Based on our historical experience with Xifaxan 200mg, which we distribute through the same distribution channels and is prescribed by the same physicians as Xifaxan 550mg, we have the ability to estimate returns for Xifaxan 550mg, and therefore we recognize revenue upon shipment to the wholesalers.

During the second quarter of 2011, we recognized product revenue related to shipments to wholesalers of Relistor, which we acquired from Progenics in February 2011. Based on historical experience with Relistor obtained from Progenics, and historical experience with our products, specifically Xifaxan 200mg, Xifaxan 550mg and Apriso, which we distribute through the same distribution channels and are prescribed by the same physicians as Relistor, management has the ability to estimate returns for Relistor, and therefore we recognize revenue upon shipment to the wholesalers.

In December 2011 we acquired an exclusive worldwide license to Solesta and Deflux with the completion of our acquisition of Oceana. Solesta and Deflux are medical devices that we sell to specialty distributors who then sell the products to end users, primarily hospitals, surgical centers and physicians. The specialty distributors generally do not purchase these products until an end user is identified. Based on historical experience with these products obtained from Oceana, and historical experience with our products, specifically Xifaxan 200mg, Xifaxan 550mg and Apriso, which are prescribed by the same physicians as Solesta, management has the ability to estimate returns for Solesta and Deflux, and therefore we recognize revenue upon shipment to the specialty distributors.

The enactment of the "Patient Protection and Affordable Care Act" and "The Health Care and Education Reconciliation Act of 2010" in March 2010 brings significant changes to U.S. health care. These changes began to take effect in the first quarter of 2010. Changes to the rebates for prescription drugs sold to Medicaid beneficiaries, which increase the minimum statutory rebate for branded drugs from 15.1 percent to 23.1 percent, were generally effective in the first quarter of 2010. This rebate has been expanded to managed Medicaid, a program that provides for the delivery of Medicaid benefits via managed care organizations, under arrangements between those organizations and state Medicaid agencies. Additionally, a prescription drug discount program for outpatient drugs in health care facilities that serve low-income and uninsured patients, known as 340B facilities, has been expanded. The effect of these changes was not material to our 2010, 2011 or 2012 financial results. Based on our current product and payor mix, we believe the effect of these changes should not be material to our future financial results.

Also, there are changes to the tax treatment of subsidies paid by the government to employers who provide their retirees with a drug benefit at least equivalent to the Medicare Part D drug benefit. Beginning in 2013, the federal government will tax the subsidy it provides to such employers. We do not provide retirees with any drug benefits, therefore this change should not affect our financial results.

Beginning in 2011, drug manufacturers will provide a discount of 50 percent of the cost of branded prescription drugs for Medicare Part D participants who are in the "doughnut hole" coverage gap in Medicare prescription drug coverage. The doughnut hole will be phased out by the federal government between 2011 and 2020. Based on our current product and payor mix, the cost of this discount was less than 1% of our gross revenue for the year ended December 31, 2012, however, the cost of this discount might have a material effect on our results of operations in future periods.

Beginning in 2011, pharmaceutical manufacturers and importers that sell branded prescription drugs to specified government programs had to pay a non-tax deductible annual fee to the federal government. Companies have to pay an amount based on their prior calendar year market share for branded prescription drug sales into these government programs. Based on our current product and payor mix, the effect of this tax was not material to our financial results in 2012 and we do not believe the effect of this tax will be material to future periods.

Additionally, the 2010 healthcare reform legislation imposes a 2.3 percent excise tax on U.S. sales of Class I, II and III medical devices beginning in 2013. This tax had no effect on our financial statements for 2012, and we do not believe the effect of this tax will be material to future periods.

Inventories

Inventory at December 31, 2012 consisted of $42.9 million of raw materials, $14.8 million of work-in-process and $32.8 million of finished goods. Inventory at December 31, 2011 consisted of $28.2 million of raw materials, $9.2 million of work-in-process and $11.8 million of finished goods.

We state raw materials, work-in-process and finished goods inventories at the lower of cost (which approximates actual cost on a first-in, first-out cost method) or market value. In evaluating whether inventory is stated at the lower of cost or market, management considers such factors as the amount of inventory on hand and in the distribution channel, estimated time required to sell such inventory, remaining shelf life, and current and expected market conditions, including levels of competition, including generic competition. Inventory adjustments are measured as the difference between the cost of the inventory and estimated market value based upon assumptions about future demand and charged to the provision for inventory, which is a component of cost of sales. At the point of the loss recognition, a new, lower-cost basis for that inventory is established, and any subsequent improvements in facts and circumstances do not result in the restoration or increase in that newly established cost basis.

We expense pre-approval inventory unless we believe it is probable that the inventory will be saleable. We capitalize inventory costs associated with marketed products and certain products prior to regulatory approval and product launch, based on management's judgment of probable future commercial use and net realizable value. Capitalization of this inventory does not begin until the product candidate is considered to have a high probability of regulatory approval, which is generally after we have analyzed Phase 3 data or filed an New Drug Application, or NDA. If we are aware of any specific risks or contingencies that are likely to impact the expected regulatory approval process or if there are any specific issues identified during the research process relating to safety, efficacy, manufacturing, marketing or labeling of the product candidate, we do not capitalize the related inventory. Once we capitalize inventory for a product candidate that is not yet approved, we monitor, on a quarterly basis, the status of this candidate within the regulatory approval process. We could be required to expense previously capitalized costs related to pre-approval inventory upon a change in our judgment of future commercial use and net realizable value, due to a denial or delay of approval by regulatory bodies, a delay in the timeline for commercialization or other potential factors. On a quarterly basis, we evaluate all inventory, including inventory capitalized for which regulatory approval has not yet been obtained, to determine if any lower of cost or market adjustment is required. As it relates to pre-approval inventory, we consider several factors including expected timing of FDA approval, projected sales volume and estimated selling price. At December 31, 2012 and 2011, there were no amounts included in inventory related to pre-approval inventory.

On November 3, 2010, we received a paragraph IV notification from Novel stating that Novel had filed an ANDA application to seek approval to market a generic version of Metoclopramide Hydrochloride ODT, 5 mg and 10 mg. The notification letter asserted non-infringement of U.S. Patent No. 6,413,549 ("the '549 patent"). Upon examination of the relevant sections of the ANDA, we concluded that the '549 patent would not be enforced against Novel. As a result of this event, we evaluated the net realizable value of Metozolv inventory and recorded a $4.0 million reduction to the value of Metozolv inventory during the fourth quarter of 2010.

Valuation of Intangible Assets and Contingent Consideration Liabilities Acquired in Business Combinations

We have acquired and expect to continue to acquire intangible assets in connection with business combinations. These intangible assets consist primarily of technology associated with currently marketed prescription drugs and medical devices, as well as product candidates. We typically use discounted cash flow models to determine the fair values of these intangible assets for purposes of allocating consideration paid to the net assets acquired in a business combination. These models require the use of significant estimates and assumptions, including, but not limited to:

• determining the timing and expected costs to complete in-process projects taking into account the stage of completion at the acquisition date;

• projecting the probability and timing of obtaining marketing approval from the FDA and other regulatory agencies for product candidates;

• estimating the timing of and future net cash flows from product sales resulting from completed products and in-process projects; and

• developing appropriate discount rates to calculate the present values of those cash flows.

Significant estimates and assumptions are also required to determine the acquisition date fair values of any contingent consideration liabilities incurred in connection with business combinations. In addition, we must revalue

these liabilities each subsequent reporting period until the related contingencies are resolved and record changes in their fair values in earnings. We determined the acquisition date fair values of the various contingent consideration liabilities incurred in our business acquisitions using a combination of valuation techniques. Significant estimates and assumptions required for these valuations included, but were not limited to, the probability of achieving regulatory milestones, product sales projections under various . . .